Sadly this is true and some even did admit that.
It will be the same mess like with Vanilla in 2019. So many people made a char there, because they wanted a new start, but the majority didn´t care about Classic. When cloning became a thing, 90% of the playerbase moved to TBC.
The result were dead realms and the same fate the HC realms will have. I am sure on release Blizzard will open many realms, with the Softcore ruleset they have in mind and a few weeks / months later, they will all be dead, as Cata or new Era shows up.
Classic, HC… should be tailored to the likes of those that identify with these settings and not some tourists just looking for a new kick.
Those that want a fresh start, should play on Era, we have so many realms with hardly more than 100 people online, just make your char there.