I think there are reasons to be cheerful.
Trans activists have been given the answer "no" in a very public way and in a way that appears to balance opposing needs and have compassion. This is a new thing. This isn't supposed to happen, almost like the Law of Gravity the flow of demands and responses is only supposed to go one way. Other countries will take note.
We've been told for years that if demands aren't met disaster will ensue. OK, the demands weren't met, is there going to be disaster now?
If Stonewall or whoever want to explain why the outcome of the consultation is wrong then I think compared to the past few years they'll have to present specific arguments. I think "you're all horribly mean" is going to be far less potent now.
The position of the Government is strongly indicative that trans means gender dysphoria. Let's see arguments presented by trans activists that this is too narrow and make clear that gender dysphoria is simply an option. Do this while the public is now a bit more attuned to this and they'll start going "Hang on, what is this?"
Time is not on the side of the trans activists. As time passes the consequences of cross-dressers and the like being within the scope of the definition of trans will start to emerge. They have already but this is currently under the radar as far as the public is concerned. It only needs one incident in the changing rooms of a large UK department store to get the public interested. GRA amendments were supposed to be done and dusted before adverse outcomes could become apparent.