coincidence - perhaps but doubt it
That is a good question, but I do think in my case a few years back, the deteriorated condition of the brake light switch had something to do with the problem, and replacement was effectively the fix.
It is a bit more complicated however, in that I also have a theory that the Cruise Problem tended to display itself more with cool or in my case cold weather.
Initially, that is back in about 2008, the dealer line was that all of the 3's tend to display the Cruise Not Available warning when the temperatures dropped below freezing. I would say that view was for the most part, correct, but the real cause of the message was the deterioration over the previous two or three years of the pair of brake light contacts and the deposition of the dust onto the pair of Anti Lock Brake circuit contacts co-located within the Brake Switch. My theory is that cold or cooler weather tended to activate the problem.
The fact that the problem has returned on my 3, I first put down to deterioration of the second brake light switch but replacement of it with a third did not resolve the very intermittent problem. Also when I took the second switch apart, this time, there was no dust visible. As such, I think LR/Ford did perhaps upgrade the contacts on the replacement switches.
Hence the thought that something else is now in play - perhaps either the clockspring or the cruise button contacts or connections.
I am now in the process of actuating the buttons per Houm WA's suggestion so that will take a few days. I will of course be watching for the message.
I might add that I have not seen the message for perhaps two months now for whatever reason. As I previously said, fortunately, the message has for the most part, not been very active on my 3 the past few years.