I kinda wish that the DetCo canon would do more with the fact that the relationship (I don't mean this in the shipping sense) between Conan and Haibara has been, or at least logically should have been, really strained for a long time.
Originally, they had this development where Haibara was really messed up, overly cautious and trying to force her maladaptive survival psychological issues onto other people, and generally not good at positive interactions. Then, slowly, Conan and the others started gaining her trust (not entirely though), and also her general mental health improved (never completely though).
But then it turned around, and started getting significantly worse. Haibara isn't really in a healing arc anymore. If Aoyama still took her seriously as a character (which, to be fair, I don't think is the case), she would be in a retraumatization arc. Conan and his allies are limiting Haibara's agency, invading her privacy, dismissing her concerns about all this, and pretending that this isn't happening while she can obviously tell that it is happening.
I think the really obvious turning point was the Mystery Train arc. Haibara even called Conan and Agasa out on it and stated that she wouldn't forgive if she were to be treated like that again. Instead of taking her hurt seriously, they just told her she should "be thankful", and dismissed her hurt as "tsundere", refusing to take her trauma seriously after using it and using her as a mere chess piece in their plans (and Akai even triggering her more by gloating about it).
Since then, Haibara has been trapped under the constant, violating supervision of these people who have demonstrated that they don't respect her, and also refuse to acknowledge that the problem even exists. It's not a situation where her recover arc could realistically continue. By all logic, she should be spiraling, getting worse again.
And maybe this is on purpose; Aoyama definitely didn't plan the manga to get this long when he introduced Haibara, and originally the slow-burn of her recovery was a good way to postpone a scenario where Haibara could actually trust Conan enough to give him the kind of information that would lead to the finale arc. But... eventually, even with the extreme slow burn of DetCo, Haibara's recovery arc and relationship development with Conan would have gotten to the point where her continued withholding of crucial information would no longer make sense... and, I guess, rather than start concluding the story at a humanly reasonable rate, Aoyama just opted to nuke Haibara's whole recovery arc and character and relationship development (not only with Conan but also Agasa).
Which could have been tragic but realistic (albeit kind of a major downer out of tune with the manga's usual tone, and upsetting to anyone who had been invested in the slow-burn mental health improvement arc), but then Aoyama can't even be arsed to take it seriously, and is now just pretending that the situation with Haibara and her relationships with Conan and Agasa are still "normal" instead of FUBAR.
It's regrettable and really shows how much everyone dragging out this franchise to milk it for more money just... doesn't actually care about the story anymore, hasn't in a long time. They'll eventually just kill central, fan-favorite, long-running story arcs rather than actually letting them conclude or evolve in a satisfying manner if that would mean risking their precious status quo (which has warped beyond all recognition anyway, so I'm not sure why they bother).
