Damon apparently did it to get money for this Water.org charity.

https://www.forbes.com/sites/jeffconway/2021/10/25/matt-damon-announces-waterorg-partnership-with-cryptocom/

https://beincrypto.com/matt-damon-infamous-crypto-com-commercial/

https://cryptoslate.com/matt-damon-promoted-crypto-com-to-support-his-water-org-charity/

It must have whet the appetite of others who backed Damon's move to proceed with this.