Analog Lab is a closed ecosystem. As I see it (as a non-employee), Analog lab has three purposes:
1) It exists so Arturia midi controllers can be marketed as 'hybrids' that come with x-number of sounds in the form of a computer-based app and DAW plugin, with built-in customizable effects and optional purchasable sound banks (some are free).
2) It's a 'gateway drug' that Arturia hope will entice owners to buy the V Collection, from which its presets are curated. Owners of Analog Lab can usually buy V Collection at a discount, the amount of which varies depending on which version of Analog Lab you own (Intro or full), and during special-offer seasons.
3) For V Collection owners, it's a central repository where users can access all the 9000+ V Collection instruments' presets in one place, plus their own user presets [made in V Collection instruments].
I stress again that I have no inside knowledge, but with those purposes considered, it would be an uncharacteristic change in direction for Arturia to open it up to allow it to host third-party virtual instruments, and have those instruments integrate with Analog Lab's assignable macros and built-in effects. Never say never, but I can't see it happening.