[1] https://conversational-leadership.net/coffee-houses/https://...
[2] https://sites.google.com/a/wisc.edu/ils202fall11/home/studen...
I think the whole relevance of the "coffee house" in the Enlightenment was that it was a space where different people were talking to each other and sharing ideas.
Does that happen in coffee shops anymore? Do strangers talk about more than pleasantries, if that?
Even in Vienna, which is somewhat of a self proclaimed coffee house capital of the world you can't really have any prolong conversations with strangers to exchange ideas. Beer houses of today are probably more suitable for discussions.
Salons in 18th and 19th century Europe generally revolved around one or a few wealthy patrons of the salon who not only funded its operations but also attracted the luminaries and intellectuals to its doors.
The analogue of patrons on the internet would be forum moderators, website owners, group creators, etc. But only to a certain extent because the owners and maintainers of an online forum are far less personally engaged with the conversation and daily goings on.
Of course the scale is much larger on the internet, and we don't actually deal with one another face to face. Banter is usually restricted as well and discussions are highly focused, in contrast to salons which were more of a social club.