Knowing unihertz they'll abandon it as soon as they have a newer model out. Long term support is not their thing. You'll be lucky to get one version upgrade (my non pro original jelly never got one despite being promised) and a handful of security patches.
I'm not even as worried about the major versions as security patches. I rather prefer my phones to last more than a year, which is kinda hard when their security stance looks like so much swiss cheese.