Nah, your lifetime license will be fine. They'll just slightly rename the products, release them as "entirely new, unrelated products" and cease updating it under the old name. You can still use the old, never updated product in perpetuity, if you want...
The first time this happened to me was a MUD client of all things. zMUD discontinued, check out the new cMUD! Also available with a lifetime license just like zMUD was!
It's not uncommon to do what you said, but to also kill the old product so that they're not available any more. Sometimes it's the exact same product, but with a different name.
Sometimes it's the exact same product, but with a different name.
That's basically what zmud/cmud was. He basically slapped a different name on a major update and declared that since it's a different product it requires a separate license and the old product would no longer be updated.
No need to kill the old product if you just let it stagnate. Things like OS updates and providing no support will slowly kill it for you, without you generating the ill will of prematurely killing lifetime licenses.
Honestly that would only mean no more updates for the 2.0 version though, right?
Like you already had to buy a new license for 2.0 so it would be like Affinity+Canvas going "we are releasing 3.0 tomorrow, sadly it's subscription only despite our pledges because blah blah blah..." except in your case it's a name change to allow them to do it without breaking their pledge, no?