most trouble is probably caused in the first few days. Doesn't matter if it's 45 or 90 days, it would have to be a few hours to be meaningfully short. Given that automating things like this is annoying sometimes, you'll be sure people will max out the 45 days…
I'm pretty sure it's the SSL seller lobby just wanting more money, tbh. Selling snake oil security.
I'm not a capitalist, I don't care about outages. I can live with Facebook being down for a few days, or my bank not accepting transfers for a day or so. Then again, I grew up with the internet in the 90s and prioritise good software and tools over availability, I guess?
Obviously at my job I have to do what my employer thinks. But if nobody cared I'd definitely do our Gitlab upgrades once a week once they're out and not in some weird "maintenance window" mandated by SLAs and stakeholders.