(Actually probably not, Space X, Russia, or China will have to send something up to rescue them, and I don't think Musk has a capsule ready for at least another 2 months.)
If things were to get that far, low key honest to god, I'd have fear in the back of my mind that the US might just lock down the media with every state apparatus available, shoot the fucker down, then manufacture a ballistic missile scare to somehow blame it all on Russia or the DPRK.
You can pry it spinning out of my cold hands, officer!
One more for the ages: This potential international incident is plausible because it can conclude in a way that doesn't significantly veer from the international status quo! If the current administration deemed this necessary to win the election, it's plausible the security and intelligence apparatus might deem it harmless enough to go forward!
This is on the basis that:
China only loses an empty capsule and possibly their already poisoned reputation as a scientific and capable modern country among imperial core libs and chuds. Annoying, but ultimately this just confirms where they already stand.
Russia loses two astronauts to this bullshit but is already in a proxy war with NATO anyway. Whatever their response is will be seen on the battlefield in Ukraine, only wasting lives that US state leadership has already demonstrated it does not care for.
This means not much materially to the remainder of the imperial core than another civilian airliner accidentally shot down by some national military.
And it all matters even less to the DPRK.
China, Russia, and the DPRK all totally ban aerospace scientific cooperation with the United States going forward.
The US population as a whole memoryholes this after the media botches the story and the conspiracy somehow becomes a culture war issue, deciding the election one way or the other. By the inauguration, it remains too partisan for any respected government authority to declare any sort of realistic official story. Despite this, they are sure to keep any discussion of this being a deliberate move by the United States catergorized as misinfo under some new, vague internet regulatory agency started by executive order and later codified by congress.
Mainstream media diligently follows along with all the recommendations like the good little stenographers they are, and large lib social media companies follow suit instinctively, for a time banning the topic for being a foreign conspiracy. It doesn't matter which country they impotently end up blaming to anyone but US immigrants from that country.
There's actually an open question on that. China's Shenzhou spacecraft was heavily based on Soyuz. But there's never been clear communication from the CNSA that the Shenzhou uses a standard Soyuz-style APAS docking system or if they modified it. It may not even be possible to dock Shenzhou to the ISS at all.
This lack of public information is pretty common unfortunately for those of us interested in spaceflight. It's not sinophobic to state that the CNSA is incredibly tight-lipped on specifications. They're very public with scientific research results relating to spaceflight, but almost never give the technical details on how they accomplish that research.
My bet is on NASA making a change to the Crew-9 flight in august, either to add physical seats or only send two astronauts up instead of the planned four. Adding new seats is theoretically possible as the Crew Dragon structure was originally designed to accommodate 7. But it may require modifications that might not be possible to complete before the flight. I think it more likely that NASA only sends up two astronauts. NASA doesn't like emergency design changes.
I will eat my hat before Bill Nelson would request a Soyuz from Russia. That is going to be his absolute last resort. Nelson is going to be under extreme pressure from the White House to make NASA's response a "made in the USA" solution.