I just got my key too....though there is one thing I wonder.....since the Digital CE isn't available yet and all game keys go towards the basic beta right now, will they know and be able to differentiate which keys are supposed to turn into CEs and which into regular editions at full release?
When I registered my key on GoG, it said "Divinity: Original Sin II - Collector's Edition", so (even though this isn't visible on my GoG account atm) I assume that different batches of keys were given out for CE and regular.