Don't know what has and/or has not been posted anywhere on his jersey number... but from what can determine, there is a little bit of an interesting story hiding beneath his Flyers jersey number; he appears to have been assigned #82... seems he wore #28 in KHL... Giroux wore #28 with Flyers... obviously, the organization would not want to stir up any possible negative vibes among the fanbase, especially with those who are dissatisfied with the treating of Giroux departure... #82 is the reverse of #28... Flyers flipped his KHL number, probably with his approval.
All of the above is pure assumption from a long-time observer of the Flyers 'days of our lives' spin-off soap opera.