In this case their program expenses are a mix of incredibly valuable things ("keep wikipedia online") and more borderline things ("redesigning the article editing UI"). When their fundraising talks about the former as if it's what the marginal dollar will be spent on, that's pretty misleading.
(I don't think this marketing is unusually misleading for a non-profit, and likely better than average; the bar for honesty in fundraising is depressingly low.)
I don't know how long ago they added the hover infoboxes, but I also noticed those. But that's a relatively small feature, at least from my perspective.
You keep harping on this, but improving the article editing UI seems like an absolutely valuable thing for wikipedia to invest in. Retaining existing and attracting new contributors is essential to wikipedia's future, and the editing experience is an essential part of that.
Sysadmins are paid to make sure wikipedia doesn't have random downtime. Time spent on bugfixing should only be noticed if someone screws up.
If you want to see what people are doing - the git repo is public. https://github.com/wikimedia
I'm guessing I'll end up either using an extension or writing something up in Greasemonkey. There might even already be a userscript out there I can use.
I'm pretty sure there's a public roadmap somewhere, and you could always follow through their bug system or PRs. Everything is developed in the open, even the infrastructure (disclaimer: I founded wikimedia cloud services, and opened up the infrastructure development).