Cobra will be available for tokens in Season 8 of the Battle Pass. It is unknown when and whether the rest of the tanks will be released.
Cobra (
Great Britain, Tier-9, battle pass reward).
Changes regarding the third iteration of the Common Test 1.17.
The tank is completely ready for release.
General:
• Equipment added: Large Repair Kit (Free).
• Removed tank tags: “Secret” and “Tested”.
• Added tank tag: “Built-in belt”.
• Price of the tank in gold: from 100 to 17 500
Gonzalo (Great Britain, Tier-8, premium).
Changes regarding the third iteration of the Common Test 1.17.
The tank is completely ready for release.
General:
• Removed tank tags: “Secret” and “Tested”.
• Price of the tank in gold: from 100 to 12,000
Firepower:
• Moving dispersion(max): from 0.25 (8.75) to 0.25 (9.25)
• Main shell (AP) price: from 705 to 895credits
• Secondary shell (HE) price: from 705 to 640credits
• Special shell (HE) price: from 4,800 to 5,200credits
• Special shell (HE) penetration adjusted from 219mm to 209mm.
• Special shell (HE) speed adjusted from 924 to 824.
• Aiming time adjusted from 3.5 seconds to 3.2 seconds.
Mobility:
Maximum speed adjusted from 35 km/h to 37 km/h.
Object 259A (USSR, Tier-8, premium).
Changes regarding the third iteration of the Common Test 1.17.
* The tank is completely ready for release.
General:
• Removed tank tags: “Secret” and “Tested”.
• Tank price in gold: from 100 to 9 800
VK 65.01 (H) ( 
Germany, Tier-5, premium)
Changes regarding the third iteration of the Common Test 1.17.
The tank is completely ready for release.
General:
• Removed tank tag: “Secret”.
• Tank price in gold: from 100 to 1,500
WG is definitely going to repeat the “bonus chapter” thing in the next battle pass, so Object 259A will be one of the candidates for the event. The others that come to mind are TS-54 and K-2, but I suppose those will be saved for marathons or just sold as is.