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.)
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.