Lets Put It This Way....
If this is cancelled just after it began then what I say is screw it & put the it up on YouTube or some other cable channel, possibly Netflix where you can watch it for free. Maybe not "free" but watch it on something you already are subscribing to.
Somethings wrong somewhere regarding "Swamp Thing" & not forget about the "tax credits story" as that's been debunked on many websites. With all the money they spent on advertising, commercials, magazine articles & interviews with the cast, something really fishy had to have gone down for them to wave "bye bye" to what was supposed to be a flagship series for their new streaming service.
As a matter of fact, let me give you a more plausible reason, I hear that Warner Brothers which is a part of Time Warner & is now a part of AT&T & it's properties are launching their own streaming service which will still be Warner Brothers, so the DC Universe will be shut down in it's entirety in the near future.
https://wegotthiscovered.com/tv/wb-reportedly-plans-shut-dc-universe-titans-survive/
Oh well say la' vie!
But again, if that's the case then put Swamp Thing where everyone can see it. That's the decent thing to do considering.