Not Specifically her, but you figured it out
I was doing some Smash speculation Analysis, and one thing I actually found out recently was that Cygames, the company, actually did More than 1 Fire Emblem music track
List of SSBU Music (Fire Emblem series) - SmashWiki, the Super Smash Bros. wiki (ssbwiki.com)
I intially thought they did one Fire Emblem music track for Byleth's DLC Pack. Not only did they do multiple, but more importantly, they actually did a Music track in the base game of Smash Ultimate (Destiny Ablaze)
So when thinking of that and how that one rumor about Katalina (which was paired with Steve from the same leaker), It did raise some eyebrows, especially considering the current situation of the Company and such. Since we know Steve was discussed really early on, and we also know that Cygames did have involvement with Smash in some form during the base game, it was interesting to say the least
Now to be honest, the rumor itself is kind of shaky since Hitagi, the leaker behind these rumors, Kind of flipped flopped at times, and they were wrong about no Atlus character in Smash Ultimate. I will say they probably had some legit info about Samurai Showdown and other info about Granblue, but perhaps their Smash info was shaky, so the rumor isn't really the big reason I Paid attention
Besides the lack of Spirits, Miis, and Characters despite the knowledge that Cygames did 100% talk to Nintendo, There are 2 theories that I currently follow that they fit right under
Tournament Theory
So I've been acknowledging the lack of the 2010's tournament since sometime after Steve came out. It was weird that the 2010's tournament was still missing so long after the other Era tourneys, and it became much more noticeable when it was still missing by the time Sephiroth showed up, since we have 2 characters (Min Min, Steve) who fit the tourney theme, So my thought process is that we would get another 2010's character sometime in the past
Well we got Pyra/Mythra, who originated in the 2010's, yet the 2010's tourney still is lacking, which could imply that yet another 2010's character might be one of the last 2 FP2 characters.
But not only that, but I've also noticed the lack of a Swordfighter tourney. Considering the amount of Swordfighters (for better or worse, depending on who you ask), and with 2 characters in FP2 (Sephiroth and Pyra/Mythra) Known for their Sword (With Masumune being Iconic part of Sephiroth, and Pyra/Mythra being literal Blades), it's absence does feel weird.
Now I will say is that we have probably weeks to go before the next reveal, so one of these 2 tourneys could still show up in some time, though I will say I would think of these 2 tourneys will get priority over a TNT Tournament if they were to come before any of the next 2 reveals. Still I will give it more time for these tour
In any case, A Candidate from Granblue, or Dragalia Lost, would likely have a Sword as a major part of the moveset, and both of these franchises were made in the 2010s, which is why the lack of these tourneys does match up with one of these franchises being represented, especially since there hasn't been Spirit events or anything, especially since there have been great times to have them (Dragalia's 2nd anniversary date)
Vergeben Deconfirm Theory
People don't like this theory for reasons, so I'll make it quick
Vergeben Deconfirm List Theory Part 3.6 (The Extension) - Super Smash Bros. Ultimate (gamespot.com)
In regards to Cygames, the Company wasn't listed on the list at all (neither the OG or Accurate version). Considering the Company was associated with a Popular leak in the early days of Smash Speculation, and the list was happy enough to list of other Japanese Companies like Nippon Ichi and Falcom which were kind of more niche topics in Smash Speculation (at the time, since Falcom has been more prominent in Speculation), I would think Vergeben would have asked about this, or be able to list of the Company on the list
Considering we know that Cygames did talk to Nintendo, In regards to this theory it does raise some Red Flags potentially
Conclusion
In Conclusion, I find the situation surrounding this company to be interesting when taking into account all these variables. Now what I could see is that since Nintendo and Cygames were collabing on Dragalia Lost around the time of Smash Ultimate's release, they may have wanted Cygames to just make some music tracks for Smash and that's that
But whether it went far or not, It's confirmed that there was discussion between the 2 companies regarding Smash, which is what the rumor did say. Cygames is the only Company we know talked to Nintendo 100%, that doesn't have some form of Spirit, Mii, Character content in the game. Maybe it could be because their main properties are mainly Mobile, but we have seen they were willing to have Mobile content, at least in the music department.