If you take all of this formal and textual events in hand with the consistent themes between the TV show, the films, and the franchise as a whole, that 2nd credits song is Sheryl and Ranka singing a concert together after she's woken back up and recovered. And the implications of all this, is that Ranka and Sheryl called out to Alto & the Vajra, and they brought him home after he got to fly around the universe for a month or so. Because as much as specific events are changed in any Macross film from their original versions, the core themes and overall outcomes are always maintained. And there's zero reason to believe this is any different, especially when all the evidence lines up with that being the case. You just have to do a bit of reading between the lines. Even if you don't think that the film is explicitly trying to say this stuff, it's very purposefully laying the bread crumbs so that people who want to believe this is the case, can do so. And thus, you still end up with fundamentally the same ending. Everyone's alive and home and happy on the Vajra homeworld. The movie just added a few extra steps to spice things up.