Every 787 flight is planned to have two S/Os. They have 150+ Captains and F/Os on the fleet once the current training vacancies are filled. This would logically mean they need close to 300 S/Os. They currently have less than 180 and that includes those currently on LWOP.
The A330 fleet now has it’s pre Covid number of S/Os. It’s long haul flying is scheduled to increase post Covid indicating an increased demand of S/Os on that fleet also.
Of course all this presumes the new variant isn’t the big deal it’s currently being made out to be.