Interesting play on words.
2016, Murray was very much known to be part of the big 4, and was a fully deserved winner of the title. I don't think you can take anything away from what he did, he played three slam finals across three different surfaces, won Wimbledon, and a plethora of other titles that year including the Olympics and then straight out beat Djokovic in the final, after having a very tough battle with Raonic early on. He ended the year world number one also, so Murray winning is hardly detrimental to the WTF.
2017 - No Djokovic, no Murray, Nadal injured and Federer burnt out. This was understandable considering both Fed and Rafa were in their 30s, Fed in mid 30s and they played a lot of tennis. On top of that Dimitrov may not have beaten either of them for the win, but he had his best year on the tour to date, took Nadal to the edge in AO and also win his first masters title in Cincy
2018 - Zverev had already established himself as a solid player in best of three events by the time WTF happened, he'd won Rome 2017 beating Djokovic in the final, he'd won Montreal beating Federer in the final, and then during the 2018 clay season he had a bit of run, and was one set away from winning three straight best of three events on clay, after beating Thiem in Madrid and pushing Nadal all the way in Rome. The problem with Zverev is that he was just as bad in Bo5 matches, which overshadowed at times what he did in best of three. The WTF format was ideal for him, and he beat two very decent playing forms of Djokovic and Federer, both who held at the time three of the four slams between them. I hardly think Zverev thought it was an exho. Also, Federer now in late 30s and Djokovic in 30s too, younger players would start to take scalps at this stage.
2019 - I have to say Thiem played some of the best tennis I have seen from him indoors, nearly pulled off what Zverev did the year before. Rafa played well also, there was a lot of competitive tennis from many of them. Tsitsipas ultimately went through, him beating Federer and Thiem back to back was still very good, also considering he beat Federer back in AO and made his first semi in a grand slam.
The events are showing a natural progression of the younger guys steadily taking over, and that is how it actually should be, the big 3 shouldn't still be dominating with an iron fist at this stage, and soon this will creep into grand slams.