Taylor Mikesell was the only Buckeye to get any senior day treatment this season. That doesn't really mean much but I'd assume these players will be back next season. I could be 100% wrong though. Walker really provided the correct amount of hustle and strength inside and a midrange shot, that Mikulasikova didn't have the confidence in her shot to make. If Mikulasikova returns and can be 100% focused like she was early in the season all season, I think they'll be okay. But I think the best rebounders are going to be McMahon and Thierry again.
As for Freshmen next season, Diana Collins is a guard out of Georgia and their top ranked recruit (#70), I don't know too much but I think she's more of a two guard but can handle the ball if needed, which, with the timeline of Greene's injury, she may have to. I don't think Rikki is the best choice at PG. For height, Faith Carson out of Michigan is 6'4" but I haven't seen much video on her, apparently her other finalists were Ole Miss, Michigan State, Xavier, and Pitt. I think most of her offers were non-P5 schools though. I'm not sure if OSU has space for any transfers, but I'd hope they could get someone with size and skill in. Seems like Posts are the hardest position for McGuff and co. to recruit in. Without any more attrition this offseason, OSU I think only has one open scholarship spot. They will have five players taller than 6' next season.