Orisa’s Halt has no effect on Bastion when he is in sentry mode. You can no longer pull him from perches or from the top of payloads. Pretty much renders Orisa ineffective against Bastion, as his gun can shred Orisa’s shield almost instantly.
(I am going to keep reporting this until Blizzard either says it is working as intended or admits it’s a bug)
This behavior currently persists on ptr.
Could’ve been a intended change to make his behavior versus displacements more consistent. Can’t be moved by non ultimate displacements unless preceded by a hard crowd control(ie. stun, sleep, etc).
Good luck getting your answer.
So then why can rein charge him and completely take him out of sentry form ? Or why can sombra hack him and take him out of sentry mode? What you said literally makes no sense
Reins charge is a pin and sombra hack is a silence. Sombras hack indirectly removes the stance by disabling his abilities. Reins pin like sleep and hook removes the players control over the character for an extended period of time. Halt similar to the shoulder boop of rein, pharaoh boop, lucio boop, Doomfist punch, Wrecking ball boop and slam, all influence a characters velocity(halt doing it twice), which bastions sentry mode makes him immune to. The only exception(I think) to this is Zarya’s graviton which my guess is only like that because it’s ultimate.
Also my bad, I over generalized hard crowd control as stuns and freeze don’t remove him from sentry mode.
Abilities that move him usually also break his sentry mode.
I’m also not saying that it’s not a bug, just backing that it could’ve been an unmarked intentional change or that it is an unintentional change due to a tweak in bastions sentry mode mechanics.
Bastion’s Sentry Mode is actually really inconsistent against Stun abilities. Charge, Earthshatter, Chain Hook pull him out of Sentry Mode, but Shield Bash, Rocket Punch, and Flashbang do not. No idea why.
The closest analogue to Halt is Graviton Surge, though, and that does displace Sentry Bastion.
It would just be nice if they confirmed this as intended behavior or as a bug. The silence is infuriating.
Sorry for the late reply but i feel that i SHOULD mention this. If what you are saying is correct, than why does the rein charge STOP once he hits torbs turret? Its pretty much the same as bastions sentry if you think about it.
Yeah kinda late 
Note: I know Overwatch isn’t always consistent, but in general the intention is for the game to have as little exceptions or for interactions to be as simple it can be. Generalization is the goal and adding numbers of exceptions just makes the game harder to learn for players.
Anyway, I’m not really sure what my angle was when I was writing that before, but besides graviton, abilities that just add or take away momentum don’t tend to break bastion out of sentry mode or move him. The exception being graviton which has a host of weird interactions such as breaking rein out of charge, disabling d’va thrusters mid-use, disabling hammond tether and piledriver mid-use, etc.
Your comparison to deployables is a bit strange because he’s a hero not a summon such as supercharger, minefield, torb turret, and sym turret/tp where none of these move once deployed to a surface, period. Orisa’s supercharger and Torb’s turret are coded similar to walls where you can get pinned or doomfist punched against them.
Also, Reinhardt’s pin only allows him to grab things coded as hero’s, besides the obvious examples it includes D’va mech(destroyed or ulting) and BOB. Which turret and supercharger behave different to things such as sleep, hack and can’t be grabbed by Reinhardt.
His sentry mode state is unique at the moment similar to orisa fortify in terms of cc reducing steroids, but his doesn’t block cc or make him a wall it just makes him immune to a majority of displacements. Since there isn’t a character with a transformation like bastion it’s hard to create a reference to his behavior. The only two current trends are, displacements don’t move him and incapacitations(pin and hook) do. Outside of the global exceptions in the game being ultimates.
Halt sequence of events is, slow target, increase momentum towards center, decrease momentum of target. Shown by how a target can be slowed and avoid the last two effects and how a mei can fly if she ice blocks to avoid the third part of halt. This does not incapacitate the user and it is not an ultimate.
Alright I’m done rambling. At this point I’m assuming that people reading these types of posts won’t be happy until a note comes out clarifying the issue or until orisa has an easier method to deal with a bastion on her own.