This is based on a real life case. An online onboarding session over Teams was prepared 24 hours in advance. Every detail was clarified, including the main PowerPoint presentation to guide it. That included all the deck slides, who will present what, and how much time will be available per slide. That gave a rough estimate of how long the presentation would take, plus how much time was going to remain available for engaging the two new potential members.
The following day the team was getting ready for the online meeting about 10 minutes in advance. It was the time when one team member suggested in the Teams chat to meet in person instead, since everyone was in the office. Moreover, she went ahead on her own, reserved an available room, and went there with one of the new potential members that had the desk close to her. Of course, this last minute major change took everyone else by surprise. Also, it created a major confusion. Nobody else could switch on a dime and join them in the room. The start of the meeting was a struggle: first the online connection to the room took some time to be set properly, plus running the slides by the designated members had to be adjusted on the fly. The team member that went to the room did not have a laptop to access the slides deck anymore. Another team member had to take over it. In the end things moved on more or less without more problems.
While things got sorted out in the end, the whole situation ended up as a good example of what not to do at the last minute. A plan agreed upon should not be changed as it did, only because a potential better plan might become aparent. Stick to the prepared plan unless there are last minute major changes that demand a different one. Once the session is over, participate in a lessons learned session and decide there how to adjust the plans for future sessions. In the same time, do not take individual decisions even if you think what you have in mind is better. You are part of a team and you should act that way. It shows poorly on you as an individual, as well as on the whole team when one changes the team plan, forcing everyone to adapt to it.