when they will not make any more money from it? I mean if we are able to use the software forever without paying anything. Maybe they know it's just a matter of time a Windows update will render it unusable.

It makes sense if it avoids any legal action. Spending money theu don't have to fight class action suit for a product that is dead to them makes less sense than allowing customers who have paid them to have a parting gift.

As far as I can tell, SPlat will run on this desktop under Win 7 Pro until this computer dies.  I seriously doubt that anything that Microsoft might do would affect it while Microsoft is still supporting Win 7.  The only reason I loaded Win 10 on the new build is because running Win 7 on Threadripper motherboards appears to be a hit or miss thing, and isn't supported by AMD or the motherboard manufacturers.

I have in win 7 machine as well. Not too worried