When the open betas stopped with a month to go before release with things not in a great state, it felt inevitable and obvious that this was going to happen.
They bundled it with 4.0 I assume because they didn't want to double the amount of work they made for themselves by having to implement BioGenesis in the old system, and then redo it like three months later in the new system. What's interesting is the speed of patches after release VS how long these bugs have been known, with many discovered in the beta or by reviewers/content creators.
They need their release build ready some time in advance (for reasons) and it's very hard to get fixes in once that happens. Delaying the release by two days wouldn't mean we got these two days worth of fixes in the release build because of that lead time, as they weren't all developed two days after that build got locked in. Unfortunately, they then have to prioritise around the demands of the corporate structure and bureaucracy rather than around the product quality. (This is what I understand from other game devs, I don't have a paradox source so I could be wrong I guess.)
The speed and rate of patches since launch has been impressive, and the communication about what's being looked at, what's coming next and when, has been really encouraging. If we were languishing on 4.0.1 for a week, then I'd feel differently about it. If they keep up this energy and don't just vanish in a few weeks time with stuff still not great, then I won't have complaints for anyone who actually made it.
If they were allowed to come out and say before release, "hey we got screwed over by the company on release timing, don't buy/play this for a few days while we fix it," that would be very funny. Devs are probably not allowed to tell us where we really ought to direct our complaints, because shielding such decision makers from any consequences from their actions is what our society and economic system is constructed for.