The next series after Macross Frontier will have Combining Mechs, Vocaloid Gynoids and ancient A.I.s.Each Macross series usually deals with a different 'alien' species which befriends humanity, so far we've had giant humanoids (Zentraedi, SDF Macross), Transdimensional/Godlike Aliens (Protodevlin, Macross 7), furry aliens and Space Whales (Macross 7 Dynamite) and Insect Aliens (Vajra, Macross Frontier). Each series also expands the scope of the setting, from Earth/Solar system to multiple worlds to the galaxy itself. The next 'species' to come could therefore come from outside the galaxy,just because there's a lack of A.I. development for the Protoculture doesn't mean other species/galaxies have the same setup. Unlike the HAL-like A.I. from Macross Plus, these might have been left dormant, or perhaps were powered down traveling between galaxies. They could have rebelled against their creators and be on the run (like the Reapers from Mass Effect) be carrying out their creators' last orders to defend territory, or perhaps continue terraforming worlds in advance of colonization. If their creators have a radically different biology (higher temperature, silicon-based, methane breathers, etc.) then some of their work might have been undone by humans trying to create habitable worlds; we've have environmentalist themes here, which Kawamori is fond of. One of the members of the love triangle might be a Vocaloid-like Gynoid. Seeing the developments in robotics for the Valkyries it's surprising it hasn't filtered down to human-scale bipeds and multipeds. Perhaps one of them is more 'lifelike' because design elements from these Ancient A.I.s have been incorporated, perhaps without her knowledge. Combining mechs might show up here (with elements from Aquarion?), as with the exception of FAST Packs, all the mechs in the Macross Universe transform only. It may be that whilst A.I. development is still slow or restricted (out of concern/fear), public use of 'partner' A.I.s for military/civilian purpose would be more acceptable, as it gives them room to learn whilst leaving humans with the final say. Other side stories here could be someone trying to reverse engineer these Ancient A.I.s to create better weaponry (villains could be a munitions/defense contractor, anti-PMC), or perhaps archaeological dig sites being attacked by unknown foes.
The original SDF Macross isn't canon. Neither is DYRL.The real canonical history is the original planned 48-episode series that was never made due to a sponsor dropping out at the last minute. Oh, and there were far more than 56,000 human survivors of the Zentraedi Planet Glassing Attack (patent pending). Either that, or the majority of the huge numbers of surviving Zentraedi could completely pass for human after becoming miclones, without the pointy ears or odd skin tone.
The last enemy in the franchise will be the Protoculture.They escape extinction by hiding near dark space (or maybe at the center of the galaxy) and spent their time repopulating their species, modifying their bodies and refining their Vajra based-technology. One day they will reappear, eager to reclaim their lost glory and subjugate the other species, bringing with them weapons that the Vajra cannot adapt to. The final battle will pit the Protoculture with Humans, Zentradi and Vajra alliance (what Macross7?).