I don't think Ares is a popular enough villain that would warrant a figure and I put Steve Trevor on par with Peggy Carter, who never got a figure. My guess is that HT has a bit more of a love affair with the MCU over the DCEU and if they never made a Peggy, I don't see them making a Steve Trevor either.
It would be cool if they do for those who want one and I hope they do, but I just personally wouldn't get my hopes up as my guess is that they won't spend a great amount of time making figures from this film.
That will be annoying for all the completist collectors out there. I suppose thinking about it if they didn't do a Returns Catwoman, which would sell out fast IMO, why would they make Steve Trevor.