This "Connected to Eternity" concept was a dumb bag... Tag Heuer (post- Biver) understood that people looking for a more luxury smartwatch would be looking at a newer version as technology evolves (every 2 years or so...). Customers who are willing to boost a 2000$ on a TH smartwatch, don't really care being able to re-use their straps on a mechanical module and giving up on connectivity ! Once the connected module gets outdated, they would be looking at an updated one with Snapdragon 3100, end then 4100, 5100 etc.
Tag should have kept the same fixing system on the E3/E4 (even changing the watch design) so that the Connected to Eternity concept wouldn't die. Using a mechanical module means people are not "Connected" anymore sadly.
And if some of them are also fond of mechanical watches, they would carry other TH watches like you do ;-)