Looks like the new target date to join SkyTeam is "by March" - sourced from:a January 5th 2023 article here: https://www.executivetraveller.com/n...-joins-skyteam

Some highlights from the article:

• “Virgin Atlantic’s entry into SkyTeam is still on track and as planned, we’ll be joining in Q1 this year,” a Virgin Atlantic spokesperson confirmed to Executive Traveller.
• previous media remarks by Weiss indicate the flagship Clubhouse at Heathrow Terminal 3 will be exempt from that alliance-wide arrangement, with SkyTeam Elite Plus members likely to be redirected to another T3 lounge.
• Virgin will also launch several “new routes as a result of the decision to join SkyTeam and to connect with airlines in the alliance,” according to Virgin Atlantic CEO Shai Weiss.
• Further out will be the ability for passengers to buy flights on any SkyTeam airline through any member airline’s website, such as purchasing Virgin Atlantic tickets via Delta, for which SkyTeam is developing a new alliance-wide technology platform of which CEO Kristin Colvile says "you will have a similar seamless experience as Oneworld.”