migration to swarm should be agreed by both parties
The other day, I was surprised that my entire conversation history with a friend disappeared, and was replaced by an empty swarm.
Today, I was given a choice to convert my contact with another colleague to swarm. Only then did I understand what happened, but the colleague was also surprised with the disappearance of past conversations.
I suggest reworking the conversion to swarm to a propose/accept exchange between both parties, rather than a unilateral move that either party can force onto the other, or at least give the other party an explanation and a chance to save the past conversation before it's gone.
Edited by Alexandre Oliva