PG Music have most certainly supported users from a long time back. I have great respect for that, but I do think perhaps they do it more than they should have. I think it's not unreasonable that people with multiple-years-old copies should be expected to update occasionally ... the Pro version is not a massive price at $129 amortised over decade is $13 per year. I do though still think PGM could offer an update amnesty to further encourage historic users to update. Then, perhaps, some of the messier anomalies could be addressed properly, once and for all. What they lose on the amnesty they'd probably save on reduced development time alone.
There is the program only upgrade for $49 that is available every year while a new release is on sale.
There is a post floating around somewhere where either Peter Gannon or Andrew said the goal is to remove all the legacy pickers once the MultiPicker has all the functionality as each legacy picker.