I think you must be only mostly right, as the Crystalline/Petals & Paper glitch went away after I posted here (as I said, for me it comes and goes), but you're spot on about notifications and ads for Crystalline now appearing everywhere.

With a lot of items the "half ancient system...", as you vividly put it, doesn't realise, as a human would, that you only want one of something at a time. E.g. if you buy an engagement ring  there'll be loads of ads to help you build up your engagement ring collection 🙂