I'm just speculating but you'd get to use the IP without needing to negotiate overmuch about it, if they're using GCP or can be retrofitted to then you could set prices at a discount but claim a market rate when discussing growth of usage, which is great at quarterly earnings report time.. or even just as an ease-of-transition to expand into Windsurf's existing user base? There are plenty of reasons, including negotiation leverage, optics, or even just appeasment to the founders or board that the original project doesn't get immediately destroyed.