If you are a frequent guest there, then I am sure if you have the right word with the right person that you will continue to have your free breakfast.
The funny thing is that several years ago, one of my frequent and regular hotels changed chains, before it did so I was assurred by their CS person that I would continue to receive all the same perks, etc as I had become accustomed even though they were not given by the new chain. One of which was breakfast, something which quite frankly I do not eat in 99 out of 100 stays. The only time I generally use it is either if I have to have a breakfast meeting or I am travelling with my family.
Low and behold, two years later I was travelling with my family and had breakfast and was surprised to see at checkout that I was billed for it. Of course my protestations fell on deaf ears as by now there had been huge staff turnover and they had changed computer systems, etc and there was no record existing that I had been "promised" free breakfast. They did not relent, and I no longer stay there.
My assistant received a call from them not too long ago inquiring as to why I no longer stay there. She mentioned the breakfast thing, and was immediately told that could have it again and they would even CREDIT me the amount from before. That's nice, I am not staying there.