I mean - most likely it is just your ex coming to brief moment of sanity and wanting to contact his kids. But let's imagine for a moment that it IS OW trying to facilitate contact between your ex and your kids - wouldn't that be a GOOD thing? It might mean she's not a completely irredeemable human being.
Still - judging from the experience of others here, most likely it's just your H poking his head up out of the tunnel. Maybe things are rocky with him and OW and this is the first glimpse of him waking up. Or maybe he just had a brief moment of sanity and remembered his kids.
I wouldn't stand in the way of them having contact, I would just monitor it for appropriateness. (For instance, if he's gonna Skype, make sure to cut it off if he starts introducing OW or bashing you inappropriately.) Just help them keep their expectations low.
