The reason why is because by now they know that it doesn't actually work (it may or may not have ever worked on the original strain, but it definitely does NOT work on the currently prevalent mutated strains). But Pfizer still gets paid for each dose administered. If you get the vax now, it is probably equivalent to getting a saline injection.
edit: to clarify, low-temperature storage is needed to keep the lipid nanoparticles (which are used to carry and deliver the mRNA payload) intact. What I am saying is that they no longer care about requiring low temperatures anymore because they know that the vax is pointless now. But they still have to pretend it isn't pointless so that Pfizer can get their money.
The reason why is because by now they know that it doesn't actually work (it may or may not have ever worked on the original strain, but it definitely does NOT work on the currently prevalent mutated strains). But Pfizer still gets paid for each dose administered. If you get the vax now, it is probably equivalent to getting a saline injection.