There can at the moment be no certainty of course however Cathay now has active 6 - 777 -300s with 15 more short term parked in AU . All of these are relatively young with the youngest delivered in 2016 (the others -over 40 are stored) Almost all are owned as apposed to being leased and they form the backbone of the CX long haul fleet particularly to the UK and the US to destinations where 1st class is required.
I can see absolutely no logical reason why, as thing open up again why this would change particularly as the 777 is the only aircraft in the fleet that can offer 1st class or offer enough seats to meet the projected demand from say LHR that daily filled 7 (sometimes 8) 777 flights daily with first always more than 90% full. Particularly London and possibly New York and other US destinations will need the 777 prior to the end of 2021.