Is Cognac getting more popular? No (at least, not yet). But the gloabal BRANDS that happen to be in the cognac game are.
There always has been a misunderstanding about "Cognac":
We hear the "Cognac" this, or the "Cognac market" that, read about a brand and assume it tells something about a category. I dont think this is accurate.
There is a Hennessy market and a Remy market and a Courvoisier market etc... much like there is a Ford, Supreme or Krispy Kreme market. There is a market for global cognac BRANDS, individual markets based on specific brand recognition.
The more successful/known they become, the less they tend to talk about the product and orient communication towards partnerships, experiences etc...
From labeling to wording on the companies' website the BRAND is front center while the mention "cognac" seem to take the back seat.
For every artisan distiller/brand owner/negotiant who has not achieved brand notoriety at scale, there is no "market" per se. It is an every day fight to tell a story, get anyone who accepts to taste the product to understand what is Cognac, demystify, get rid of the bagage the word comes with and do one's best to explain within that framework why one is different.