Hi and welcome to Arturia forums.
Your old and your new plug-ins don't have the same ID, and the preset system is different. You can have both the old and the new plug-ins installed. I have.
I would re-install the old plug-ins on the same path as before. Then they should load again in your old projects i exspect. I don't use Ableton, but i assume the needed data is in the old files, unless you have changed anything in them allready.
From there you can either:
1. keep it like that or replace them with the new plug-ins manually and select the preset in the new plug-in manually too. But remember that you can't be sure the new plug-ins will sound the same as the old even when using the same preset.
2. Convert the old tracks to audio. This is also the way you are most secured. You never know when something is changed.
Hope this helps.