I was secretly hoping this day would never come 
Note that those methods have the following comment :
NOTE! This method will eventually be deprecated!
So before you remove them you may want to actually mark them as deprecated for some time.
Last year I did a poll about plugin parameters (here), and 26% were still using custom parameter classes not inheriting AudioProcessorParameter. When using such custom parameters classes you can’t simply call addParameter(). Changes are much bigger, do not underestimate them please.