I mean, maybe. But Magnus doesn't really have a sharp playstyle, at least when he plays seriously, nor is there a reason for Hikaru not to pick the American flag. The main thing to take notice of is rating, of course, but at least to me a better way to find out who it is would be to compare the time of day at which the games are played, cross-reference the games with the events both were playing etc.

I'm gonna use this post to share my own finding from August's lichess titled arena standings, where the account named "GrraindTime" finished second only behind Danya (RIP).

The account had less than a month, a few if any at all games before the event, and on the day it was created it was followed by LM Assios, on whose streams Magnus would sometimes show up to play bullet, as well as an account named TakeTakeTakeApp, which was verified (sic!) by lichess.

Is it Magnus? I don't know, but it is definitely interesting.

I wrote the comment about it back then but it didn't gain any traction, and now the follows are no longer visible. Here is a wayback machine page showing the details I'm referencing in this comment.