When things come up with other teams, you’ll have a catalog of tasks that were done to show why you didn’t have the same issue. The work was done, just at a better time to avoid downtime.
Speaking from experience, this does nothing. If you're at a company that is okay with average performers, then absolutely, 100%, fix all the bugs in advance, make the system rock solid and stable, prevent downtime, be a good engineer.
If on the other hand if you're at a company where 10% of people must get stack ranked and PIP, or at a company where "meets expectations" actually means you're going to get the stick, and you're supposed to be "redefining" expectations every year ... then yeah, don't do anything preventative. The optics are better when you take the 3am on-call and fix the issue (that you secretly knew in the first place would happen some time in the future in your coworker's code, and already knew how to fix -- but don't actually fix it until it surfaces). Be the savior that the VPs praise in the next meeting, that's your insurance against the PIP.
They set the rules of the game, you just play the game. The rules were their choice. They could have chosen different rules.