FYI your very reasonable concerns about this change prompted me to take another look at the existing code. I have tweaked the validation code that produces the 404 errors on failure to be a little more forgiving. Now you're allowed one fewer parameter in your method signature. This means that existing action URLs should be fine even without update. The $bID argument you still added to the URL, and will be the final argument in the function, so it can be used to check against, but if you don't include it it won't fail it won't fail.

https://github.com/concrete5/concrete5-5.7.0/commit/664982c0e871d270...

It's still a good idea to update your add-ons, and to support this $bID check (so multiple instances of a block can appear on the same page together) but it's not required to continue to function.