The increase in pharyngeal cancers may come from oral HPV infections specifically, not "libertine sexual habits" per se. It's only gonna be a few more years to find out, if HPV is related to the increase in colon cancers in young people, since the broad vaccination of teenagers is going for some time by now.

I think, it's also worth considering the fallout of the AIDS scare messing with statistics here. PrEP, education on and treatment options for HIV may have caused people (including heterosexual) to use less protection in recent years, unfortunately, since other STIs are less scary and stigmatized. I doubt rates of oral and anal sex have increased that much.