I wrestled long ago, have done no-gi for 2 years, and just recently started taking a wrestling class at a university (PE). Here's what I notice going back:
Takedowns are in a different league. I've never been taken down in no-gi competition (well, 4 tournaments), but the college wrestlers school me. But less than they did a few weeks ago. Every time I do takedowns, I remember more of what I once knew, and even the beginners in the class have progressed a lot. It will help.
Pace is totally different. Call it spazzing if you like, but a wrestler will make you work a lot harder than your average BJJ guy in class. I have a decent top game in BJJ, but I have to work to hold college wrestlers down, even from a dominant position. They don't rest.
In fact, pace is the biggest difference I've noted between class rolls and competition; wrestling will get you used to a faster pace that you may need in the latter (or MMA competition).