There's a good argument that there is plenty of evidence out there that Rees' gameplans and adjustments are lacking...
But this year is also different for him, so calling for his job, or calling the lack of getting a veteran OC to pair with Freeman a failure, feels a bit early.
I know, I know... you don't want HC's or coordinators learning on the job at a place like ND, but I think Tommy is through the learning process. Now he's on the 'finding himself' stage after BK's departure. He's on his own, building gameplans and accounting for adjustments. He's the head honcho on offense, with no voice above his (save Freeman's for in-game situational stuff I'm sure, like 'force it to Mayer here' or 'deep shot right now').
ND needs to find its identity, and that takes a few games for any team, unless you're loaded at QB and WR and KNOW you're going to be airing it out 65% of the time... like the team ND just played. That was a tough spot for Tommy to put ND's full identity on display, if he and Freeman even know what that is yet, because of the situation both at QB and based on the opponent.
There were definitely some head-scratching calls. There was a play that almost looked like a counter-trey, but there wasn't actually a play-side threat, with zero offensive players following the pulling OL. Maybe this was an attempt at a poorly-designed misdirection... or maybe it was a miscommunication from a green QB, or a play that should have been a read but was a hardline 'give no matter what' instead. The lack of screen game to play off of ND's own conservative calls against OSU's aggressive front 7 was also alarming, but they seemed to be supplementing with QB draws as an option for Buchner to check into.
And you could see the merit to some of it! Buchner made an excellent decision to check into a QB draw look against a friendly defensive front, and it even had a motion to clear out the safety. It's a good install from Tommy, and great recognition from a first-time starter at QB against a veteran DC... but Ohio State had double-twist called at exactly the right time to ruin the rush lanes. Your OL can't invite the DL past the pocket if all 4 guys on the line are running stunts. That's just bad luck in a moment of great preparation and setup.
There were also some effective shots taken down field, and Tommy knew when to target OSU's single coverage. Buchner either missed the throws by a step, or the OL wasn't quite in-tune with handing off pass rushers. Both things will clear up with time, and make Tommy look like a genius.
There are some concerns. There are also reasons for hope.
TL;DR
It's too early to panic you dorks.