Sure, but the point stands that the bomb wouldn't be available for a few months. And pulling the plug on aid would definitely be a problem for them eventually, but just because you cut off the start of a supply pipeline doesn't stop the rest of the stuff that's still in the pipe from flowing ... at least when the pipeline is metaphorical.
It would be a very rough few months for the allies before the bombs would start becoming available and even then it's not guaranteed that the soviets would surrender. It's simple historical fact that the western allies left Eastern Europe to its fate, but the alternative would have been much, much bloodier for the west than you seem to imagine.
As for Patton, even the author of that book
apparently says there is no proof backing up his speculation.
Douglas Bazata,who shot Patton,was OSS agent.And assasin who delivered poison was not polish,but NKWD.
Patton hide 1300 polish partisants who get there from soviets - they had reason to hate him.
And fear,becouse he knew that their army was shit.
Soviets wers as much 2nd world army then,as they are now.That is why they must win in hospital using agents.
And,if you think that one Patton officer could not be OSS or soviet agent,then you really do not knew how they operated.
They were shitty soldiers,but brilliant secret service.
About war - why wait for A bomb? B.17 would destroy soviet logistic hubs,and P.47 would destroy soviet artillery.
If soviet fighters try to intervene,they would drop bomb and schoot them.
When soviet heavy tanks advance,they would drop napalm bomb on them.
Soviets had numbers,but notching more.
Their tanks,except american and english,was shit and stop working after 2 weeks even if they were not destroyed.
Their artillery was not trained,so they need to be field in rows firing wheel by wheel - ideal target for USA planes and artillery.
Their infrantry,except parathropers,only knew how to attack in waves.
And,their fuel come from two refineries - Baku and Ploesti.USA B.17 would burn both in week,after that soviet could fight on horses.
Not mention,that they were slaves.They fought germans,becouse germans first murdered prisoners,and later was loosing.If americans keep winning and do not kill prisoners? they would mass surrender.