To motivate his crew, Cortez burned his ships upon landing in Mexico. My recommendation is that if your intention is to switch...switch!
Just make sure that you select a program that will fit (most) of your needs. I was changing computers last night and today brought up the TMG website, only to be blindsided by the announcement from last year about the program being discontinued. (Obviously, I hadn't been very active in the last year :-) ).
My first thought was, "now what?"Several years ago I spent an inordinate amount of time creating custom tags for things like city directories, and rearranging census tags, etc. I'm not expecting very many (if any) programs to play nice with those tags. They'd certainly be lost in a GEDCOM export.
On and off, I've looked at GRAMPS as an alternative. It's open-source, which means that if the current developers decided they were tired of maintaining it, someone else could pick up the ball and run with it. This means it will always be around in some iteration, and will be able to be modified when new O/S challenges arise.
Last year I asked on their Facebook page about importing custom tags. The developer was nice enough to say to send him a snip of my database and he'll see what happens. I didn't follow through so am not sure how robust of an import will happen. There was a TMG2Gramps importer written a while ago. But, that was based upon TMGv6, which is obviously pretty old.
For now, I'm going to continue using TMGv7. But, I'm going to actively be looking at other programs to see how well they import my unique dataset. It may come a time where I have to "burn my ships" and move on. But, until I'm either comfortable with the results, or can at least live with the consequences, I won't be making any knee jerk reactions.
FWIW: TMG ran fine on Windows 8, so I'm assuming it will also work fine under Windows 10. That means you've got a while to use it beyond the 2020 date I've seen mentioned.