>>529095405
heirlooms are for old frames who aren't quite up to snuff with the modern game's designs according to reb
the frames that have one so far are frost, mag, ember, and rhino
frost and mag were tennocon 2023 exclusive too so if you didn't get them then you're shit out of luck
here's a list of all the frames that released in the first couple years of the game.
the pattern for heirloom releases so far have been male/female (released together), female, male, female
so it is likely the next heirloom will be male
vauban already has an heirloom design, so it will probably be him

and then after him (so sometime in 2026 probably) the female candidates are trin, nyx, banshee, saryn, nova, zephyr and mirage