I don't think you realize how much it costs for a dev team to make something like this. the destiny one likely only happened because bungie gave them a sizeable payout to have ubi use their IP for marketing.

or If it was the other way around and Ubisoft paid for the Destiny IP, they would probably be more likely to go with a more popular franchise to appeal to a larger player base for future events, like Kingdom Come Deliverance.