I think allies should be allowed in queer safe spaces. Actually, I ENCOURAGE them to be in queer safe spaces.
I think that there can be appropriate times for allies to be in queer safe spaces, but that a large majority of the time the entire point of a safe space is to be AWAY for cishets, which includes allies. The point of the tweet in question was to say that “allies” who insist on being a part of queer safe spaces are misunderstanding why those safe spaces exist in the first place, and that those “allies” should not be there unless specifically invited.
I think the danger is in assuming you get to always be invited into those spaces
I have a button that says “Queer Ally” that one of my lesbian friends gave me. She bought it for herself at pride because she thought it said “Queer Alley” but then realized what it actually said and then gave it to me as her token straight friend lol. I wear it on my coat along with all my other political pins, so lgbtqa people know that I’m a safe person to be around. But I don’t go up to anyone to tell them I’m their ally. I hope me wearing that pin doesn’t make me a shitty ally.