The Asparagopsis supplements I think you are referring to are arguably clever, but
> Before these were invented we were looking at a situation where meat consumption (or at least beef) may have to be phased out.
They haven't really changed the game, at least not yet. But assuming optimistically they can reduce cow methane emissions and downsides can be avoided [1], the magnitude of the reduction [2] probably will not make or break the continuation of the cattle industry.