And there is evidence that the vaccine has no benefit on those infected [1]. Either way, this is clearly an open question, and avoiding the vaccine if you have been previously infected is, at minimum, a reasonable stance.
Just a quick edit here to say that your paper specifically doesn't show any immediate ability to be infected by the disease having recently had the disease. However the point that having the vaccine can help beyond that is what I cite here. There are other papers that show that having the disease is less likely possibly to result in immunity compared to the vaccine, but I don't have that handy nor a good way to search for it right off.
This isn't a study. Looks like they're recruiting people for a study at the moment. They have anecdotal self reports that 30% - 40% of people with long covid felt better after being vaccinated, but they also say 10% - 15% felt worse. Seeing how subjective this is, I would wait for the study to happen, and for the dependent variable to be something other than self-reports.
Even so, for people who have been infected and don't have long covid, it's entirely reasonable to skip the vaccine, as far as we currently know.
[1] https://news.ycombinator.com/item?id=27453721