That teaser is iconic imo. I didn't watch the March 8th, 2018 direct live, but an hour or so after it ended (I was busy so i couldn't watch it on time) i checked a subreddit to see a sumary of the direct....and i saw that fire logo on the first post....i was "BRO, WHAT IS THAT.....SMASH 5? FOR REAL?" Back then, a some of us weren't expecting a Smash 5 reveal this "early", so i was in disbelief for a few minutes, that fire logo was hype as hell lol.
I still remember the Smash 4 Deluxe vs Smash 5 debates after the trailer, god times lol.