Nope. TP-Link has locked out OpenWRT. It's not a highly effective lock, but it is real and they actually deployed it as an update for existing hardware in the field and for new sales. They're not going to revert to the way things were and instead are trying to develop a new security strategy that clearly won't be feasible on the existing hardware that is now locked out.
And it's not like any router vendor ever actually actively supported third-party firmware; it's just a matter of how much DRM they use to interfere with it.