No harm in messaging them just to say thank you.
If you’ve just stepped out of uni into an internship you still have a lot to go, but getting through college, uni and into an internship is an achievement in itself. They won’t be disappointed, they will probably be proud that the work they did encouraged you to stay in education for as long as you did!
I’m sure I remember when PA was first announced it was the first ludicrously overpriced game for early access, and they said the reason was that they only wanted people truly invested in the game to give feedback. It was a clear attempt at a money grab from those most excited. Given this is the same people I’m not surprised by their tactics.