As someone who's favorites are these two and have been following their relationship for years, I think it's safe to say they should stay apart now only because...there's nothing going on right now.
Cause during the revival, they were officially back together and having them as a couple during the movies was great, but the reason they broke them up (imo) was to spice up the chemistry between them for the new show.
Sadly, in the first half of the 2015 show they didn't deliver what I was expecting. When the reboot happened for the show, they had Kermit and Piggy working together and interacting, not constantly fighting and being apart.
I still think the finale of the 2015 show was the best character development ever for Kermit in terms of the relationship, but it is sad to think they flushed all that down the drain when he confirmed at the Vulture Festival that the breakup was the same.
Honestly, I have no idea why they chose to go that way instead of explaining anything but..at this point do we expect a Muppet Canon to be consistant? Not really lol.
So, it probably won't be until we get the next movie , tv special, or tv show that they focus on them again. Right now just isn't the time to do that. But also, I think they REALLY need to fix the writing between them first before they do any of that because from the Hollywood Bowl interviews, I'm not happy with what I saw.
I'm hoping to write a long article about my current feelings on them in the future.