"TIME OF DEATH"
It's the sort of thing that's happened before with 'The Dead Zone' (suddenly a new President and Vice President of the United States) and 'Alias Smith And Jones' (due to the death of Pete Duel, Hannibal Heyes was then played by Roger Davis.)
The great thing about the Toobworld Dynamic is that it's malleable. If the scriptwriters can go back and change their show's own history, I can do the same with the TwD. And after some consideration, I think I can modify that decree somewhat.
From now on, as long as the Flash or Barry Allen is not mentioned or seen in the show, then we can assume we're watching an episode of 'Arrow' which is set in Earth Prime-Time. After all, just because it got shunted off to an alternate TV dimension, that doesn't mean it ceased to exist in the main Toobworld. Should Barry Allen or the Flash show up again, then our P.O.V. has switched over to the other world. (I'm thinking the International House of Remakes. Nah, that's not a very good name for the Land of Remakes. Gotta keep looking....)
And when it comes to him being mentioned, I might be able to loosen the rules a little more and claim that they're talking about the original Flash. But I'm kind of committed to the theory that the speed powers exhibited by Shipp's Flash have dissipated, if they didn't outright kill him!
The reason for my change of heart is Black Canary, mostly. I'd hate the idea of losing her to another world (but not 'Another World'.) Plus there have been so many other great characters translated from the comics who have shown up and who have never been seen before in Earth Prime-Time - like Deathstroke, Count Vertigo, China White, Solomon Grundy, KGBeast, the Dollmaker and the Huntress. (Her previous appearance was in 'Birds Of Prey' and that had to go to a different TV dimension, probably Evil Toobworld. Solomon Grundy also appeared before in "Legend Of The Superheroes", but that's in Doofus Toobworld. Most of the others may have appeared in animated series but of course those all go to the Tooniverse.)
Ra's Al Ghul has been mentioned on the series, and his daughter Nyssa and his League of Assassins have shown up, but we have yet to meet him.
The latest to join those ranks, and who was also instrumental in changing my mind about the status of 'Arrow' was the Clock King, an alias used by William Tockman.
Unlike the Huntress and Solomon Grundy, the Clock King has appeared in Earth Prime-Time before. And yet I think the main Toobworld can support them both. That's because "Clock King" is an alias which could be assumed by anybody. And during his two-episode stint in 'Batman' during the 1960s, his name was never mentioned as being William Tockman.
And so what if it was? There has been enough time elapsed for the Tockman family tree to feature both grandfather and the grandson named after him.
The Clock King had no special powers, just a keen sense of timing and an obsession with Time. (It's a trait shared with the late Clockwise.) So there's no problem with two such similarly named characters with similar modus operandi existing in the same TV dimension. This is unlike the case with Barry Allen becoming the Flash. It's such a random occurrence - working in the Central City police forensics lab, getting doused with chemicals which give him super-speed, that red costume with the lightning bolt - that it would stretch the willing suspension of disbelief.
Although I have to admit.... I am tempted to try and get away with it if the reports of John Wesley Shipp being a recurring character on the new 'Flash' means he's playing Barry Allen Senior! (However, I suspect he'll be Jay Garrick, the Flash from an earlier period in a parallel dimension.)
So them's the New Rules: if an 'Arrow' episode features Barry Allen or the Flash, or probably even mentions him, then that's an episode which belongs in the Land of Remakes. (Toobworld Remake? Simple and definitive......) But if it's Flash-free, then we're back in Earth Prime-Time.
By the way, this episode did have mention of Central City - Mrs. Lance, the mother of Laurel and Sarah, is now living and teaching there... and has a new man in her life, much to the chagrin of her ex-husband. There is no problem in this because Central City does exist in the "Telemerica" of Toobworld. No mention was made of the Flash so it's all good.