Would you guys think MP would cause a stir if the band recorded this SFAM tour and release it?
I suppose that depends on what "cause a stir" means. If it means say something stupid/ill-advised via social media or an interview, then maybe, but I think it's equally as likely that he says something not stupid or benign or nothing at all. Unless the separation agreement that I assume was signed after he left the band prohibits the band from doing such a thing (which I think would be REALLY weird), then he has no ability to anything beyond that.
would you think it would be a smack in his face?
No, and I don't know why folks constantly think or ask about MP being "smack[ed] in his face" every time the band does something with material he played on.
He didn't write all of it, but he wrote some songs, produced the album with JP.
Right, and then
he chose to leave the band.
I would think he would feel he is "being replaced" or being "re-recorded" in the album.
If he were to think/feel that way (and I don't think he would), then he would be an immature cry-baby. I'm honestly not sure what "'being replaced' or being 're-recorded' in the album" might mean, but nothing the band does now impacts what that was and who played on it. It's not like they're having MM re-record all of the drum tracks and replacing MP's tracks and re-releasing the album (a la Blizzard of Ozz and Diary of a Madman). If I'm counting correctly, Live at Luna Park contains 14 songs from the MP era, and Breaking the Fourth Wall contains 11 such songs (including 4 from SFAM). Was that MP being "'being replaced' or being 're-recorded' in [those] albums"? Should Kevin Moore feel that way about all the live releases containing songs from WDADU, I&W and Awake, and should Derek Sherinian feel that way about live releases of FII material and ACOS?
To be sure, MP made some petulantly childish comments in the couple years after he left the band, but I think he's demonstrated that he's well past that sort of nonsense by now.