This issue happens for every major update, and there’s no way to 100% avoid version mismatches until everyone has upgraded to the new version. Just be patient, and once everyone is forced to update in a few days you can raid and revenge to your heart’s content.
Google and Apple stagger the release of new versions of software from their stores so everyone doesn’t end up trying to download it at once and overload their servers. Sometimes people get it quickly, like I did last night, sometimes it takes longer, in one case for me literally just a few hours before the old version support was turned off.
Not having updated is not necessarily the result of some vile plan so cunning you can put a tail on it and call it a weasel, it’s quite often just the obscure and unknowable vagaries of Google release algorithms making people wait on tenterhooks to see the latest version.