When will I get WiFi 6

Wifi 6 is avalible everywhere, you just need a wifi 6 router 

You need to try and get upgraded to the Hub5 which has wifi6

They are unlikely to simply swap one for you as Hub5' are prioritised for new 1GB customers.  Even customers upgrading to 1GB are not guaranteed one as a Hub4 is 1GB capable - albeit Wif5.

You could of course always put your current  Hub into modem mode and get your own Wifi6 router or Mesh.  Good introductory ones can be had for ~£50 - pay more for more features.

If you do spend money on your own networking equipment you should certainly but at least a WiFi 6e or even WiFi 7 unit.