I think this is the important thread you need to read.
FWIW this is the key section which I believe applies to the question you asked.
“The weight used for category enforcement calculations in watts/kg (using zFTP and zMAP) will be determined by the average weight of all weights that were in effect at the moment that certain key peak power values of the power curve were set (within the last 60 days).”
The way I read this - Changing your weight will only effect your CE category if the ride, where your weight has been ‘artificially’ changed, results in an improvement in one or more of your 4 key peak power values. Your changed weight will not effect CE category calculation if you do not produce a new peak power value.