"I had a tendency to do “worst case disaster planning”. Ie. assume the worst is going to happen and make sure I have a plan on how I’d deal with if it does."
its definitely not the same as
"very socially anxious for example and will do what he can to avoid being in a big crowd/ talking to people he doesn’t know."
I'm not sure that having a plan to deal with things that go wrong such a bad thing? It's what I do if we are going on holiday. I check and check the flights/transfers/accommodation, organise the insurance -
You've got children, so of course you want to have a back up plan and not leave everything to chance. I don't think that is something you should feel bad about. It makes you a responsible parent.
I've been recently nagging DC about making sure they have adequate holiday insurance as they thought it was for lost luggage, not realising its for medical insurance.
Do you think you assume the worst because you are living with someone who is very depressed and can kick off, so you are more aware of making sure things run smoothly to prevent this?
His social avoidance is more serious than advance planning and prep IMHO. It's more likely to set a poor example. Your planning however, just shows them how to take care of themselves and having back up plans is no bad thing.