I did have a thought on this that I'll be curious to see handled.
Matt has apparently been retired from costumed vigilantism for a bit now, based on his conversation with Fisk. A line was crossed, etc., and he's not Daredevil these days. Which makes sense, and I look forward to seeing how they handle that (I have theories on what prompted him to walk away, specifically that he killed the man who killed Foggy- I think that brief shot of Matt, Foggy, and Karen was a flashback to the night Foggy died.). Whatever the reason, Matt isn't in costume anymore.
...you know, except for when he was in She-Hulk. Which was, based on timeline, pretty recent. So...
But hey, that was a goofy little side thing, and maybe his appearance there isn't canon somehow, with a nice easy explanation about how he-
-oh, the yellow suit from the show is in his closet-o-suits at the end of the trailer. Hmmmm.
I'm sure there's a plan for that plot hole, but for now it feels very much like there's some explaining to do.