EA Sports will likely remove this card as soon as they can from FIFA 23 Coins entirely. Anyone who has him on their team will keep their duplicates in Ultimate Team mode. However, these will be transformed into non-tradeable versions so that they are unable to be sold on the marketplace.
This would also mean you will see the card taken from all packs, and will not be available. Any future objectives or events that could have rewarded cards in FIFA 23 will also be modified. In the meantime, EA Sports might release an exclusive Mwepu card to recognize his achievements during his short career.
Mwepu is also likely to remove him from careers mode and offline matches. On the other hand the players will still be able to enjoy the different licensed players in Brighton and try them out on the track in their career. If you're a talented youngster, this is a huge loss however, it's to be a wise choice in hindsight.
The football community has prematurely experienced a loss of many players throughout the years because of accidents, illnesses and many more. We would never have thought of this to happen, however, it has.
Members who hold the card have access to the services for the time being. The situation will be quite sad for the entire community since Mpewu began the season in a positive way and buying FUT 23 Coins was rapidly emerging as a top performer on the field.