Prior to the new Bonvoy merger that rule was in place... you could transfer an unlimited amount of points for an immediate booking.

That option was written out of the T&Cs when the Bonvoy merger finalized.

I believe you also used to be able to bypass xfer limits for spousal accounts but that option is now gone as well.

Rules now:
- You can xfer out up to 100k per year
- One account can receive a max of 500k points per year

You may be able to do the xfer like above and also buy/gift points but the T&C doesn’t address that specifically