You claimed that "THEY" changed the definition, based on a dictionary. This would imply that the definition was changed during covid to include "mandate sceptics". The link shows that in 2018 it included "[...] laws that mandate vaccination". The only real difference is that the former definition uses the word "laws" and the current one "regulation". While the two words are not interchangeable, the definition on merriam-webster includes laws as a type of regulations.

Calling this a meaningful change of its definition that "THEY" did is nothing more than pedantic anti-vaxx bullshit.