The internal management shift within Honda, after the 2021 championship win, made them reconsider to the effect they didn't want to dispose of IP as originally spoken about through their withdrawal notification.
In addition, if RB took on that IP they wouldn't be considered a NEW engine manufacturer,, as such the consequential allowance to research, budget and bringing to fruition a new power unit under those consent rules would not be available to them. Effectively no transfer of existing IP took place, I believe.
Staff recruitment obviously comes with previous experience, which is transfer of knowledge,,and quite acceptable of course.