Dr Poison in the movie Wonder Woman is revealed through the film to be Isabel Morrow. I hadn't heard of Dr. T O Morrow having any relations in other DC media, but the fact that they chose the same surname for two science-based villains is rather interesting.
Is there intended to be a connection here, or is it just coincidental?
It's just coincidental.
The villain in Wonder Woman is based directly off the same character in the source comics, Doctor Maru (a.k.a. Doctor Poison). In the comics, she was introduced in 1942, originally as a Nazi spy named Princess Maru, who used a face mask to hide her Japanese ethnicity. Later, her granddaughter also took the alias Doctor Poison and began working for the Russians. In each case, she was an enemy of Wonder Woman, specializing in biochemical weapons.
Doctor Morrow is an entirely unrelated person in the comics, introduced in 1964 as an enemy of the Justice League. His name is an obvious, in-universe take off on the word "tomorrow" (he claims his real name is Tomek Ovadya Morah but he calls himself T.O. Morrow because he likes to study the future).
As far as I'm aware, there's no relation in the comics or in the DCEU between the two characters.
