It's not a signal of anything. This is a typical development deal. The partner is risking capital developing B-UP, and wants the option of capturing the value enhancement of B if that proves successful, because it would mean that B-IBD AND B-OM are then more likely to be successful too.
This is done in pharma, race horse breeding, real estate, etc. When RE developers develop a property, they'll option the (available) surrounding land.