Yes, 7.X and up will support the older accelerators and all code up to what evercode version comes out when it goes EOSL.  Not sure what happens with legacy equipment support after that. The new A100 requires a minimum of 7.0.2, but it is not required that you swap out the older nodes once you upgrade OneFS.
Will the old accelerator nodes support 7.0 andabove or are we forced to replace them with A100s when we upgrade to 7.0.2.X?
Will the old accelerator nodes support 7.0 and above?