I think you're missing the point. You can type whatever you want as you're loading in. I've seen plenty of 'First time here, anything I should know?' from tanks. From my experience, people are supportive and happy to help out in these cases. I've equally seen casual banter on loading in that sets the tone for a more conversational run. But to suggest that a strategy meeting at the start of a dungeon is at all standard is ridiculous.

Part of socializing is being able to read the room. People in a dungeon are generally looking to get in and out. Dungeon Roulettes are this game's equivalent of a quick match, for people who don't have a lot of time on their hands but want to dip in and out quickly without controversy. Some people will be in the mood for banter, others will not.

Part of socializing is also being able to communicate non-verbally. This is actually an essential skill in harder content because you have to be able to read someone's intentions from how they move around a resolving mechanic. You know those situations where two people can't decide who is going to what safe spot, resulting them both moving to the same spot multiple times before wiping? Entirely dependent on your non-verbals.

Again, if you understand how to communicate effectively, all of this is a non-issue.