This is a good approach because you can invite any members you chose and probably can remove members from the conversation too. It essence, it is the same as a group. When you start the conversation just give it a title that is reflective of what the group / conversation is about.
Groups will not be restored because the current platform does not support it. I am sure that it would be cost prohibitive to incorporate this into the current format.
However, I am sure that certain changes can be made to the format at a nominal cost. That is really the purpose to the donations, to cover the expenses of minor changes, monthly web site charge, etc. I'm not sure of the cost of this new format but it probably exceeded the total donations for a typical year.