When building my rails application I was not yet aware that there were certain class names or words that are reserved for use. I made a class named "Protocol" (class Protocol < ApplicationRecord) which netbeans IDE says is overridden.
I can see now that "protocol()" is a public method in rails, hence the flag by netbeans: https://apidock.com/rails/ActionDispatch/Http/URL/protocol
However, I have named a class as "Protocol", and have not named any methods as "Protocol". It will take me quite some time to fix this mistake (rename all the associations and remigrate the tables and move the data across etc).
Everything seems to be working fine even with this problem. Can anyone explain what if anything might now be broken in my application if I do not change it?
No, you should not be concerned. There is no Protocol class in Rails and, even if there was, it would most likely be namespaced.
You can test if it is reserved by generating the model through the command line. As an example, if you try to generate a model named ActiveSupport...
$ rails g model ActiveSupport
you'll get
The name 'ActiveSupport' is either already used in your application or reserved by Ruby on Rails. Please choose an alternative and run this generator again.