Great, thank you!
The "wow really?" was in reference to employees not being given notice about Byleth, and, granted, this is my interpretation, but the "even if you say 'that's not the character I was picturing', I hope you don't have any hard feelings" seems more about anticipating the polarity of Byleth than insinuating the character wouldn't be known.
I mean, in this new tweet, he says "you may not know the new fighter". It's... a bit different. But of course, all we can do is wait and see.
To be honest, that seems kind of a standard hype-building comment prior to the show. At least to me. I mean most of the characters have been surprising for one reason or another thus far.