Originally we were worried about people accusing us of "locking content behind other expansions" or somesuch. But there are consistent calls across the community for more ideology/Biotech crossover, and it makes perfect sense design-wise, so we've been pushing on this internally (in addition to all the general improvements in ongoing updates).
Hopefully it'll be on the unstable Steam branch next week for public testing and full release soon after.
If you want to track the builds as they go up, they're on the RimWorld official development Discord server.