In addition, there were also three Break The Bank's (1948-57, 1976, 1985) and two Strike It Rich's (1951-58, 1986), each one completely different from each other. Also, this is especially since the last 2 BTBs were only 9 years apart.
In my opinion, since the titles are not trademarked and the previous show is out of production with no plans of revival or broadcast, the next producer would be free to use the title, provided that the new show is not a blatant ripoff of the previous show.
In addition, the upcoming "50 Grand Slam" will be different from the 1976 version (according to previous posts here).