If this had been said about women's basketball, is the response from Oregon MBB the same? I'd say probably not but we can't be sure. More interestingly, though, if this had been said about women's basketball, is it sexist? I think you could argue no just as easily as you can argue that the tweet in question was sexist. Sexism falls under the category of power disparity and power disparity is ultimately what feminism tries to interrogate. If field hockey can be belittled, then so too could women's basketball, I'd argue. Otherwise we're assigning a level of importance to women's basketball that can then be used against us - and has been used against us - as a punchline for the current state of our athletic department.
It's definitely a bad decision to tweet that out, not because it's unfunny but because you can't disparage another sport when you're the official account of Oregon basketball and by association the school as a whole. Not a big deal, but I can see what people would find it problematic.