A lot of people have reported that they're able to purchase gametime tokens after reaching 36 tokens in 24 months cap. Battlenet balance did not make it to 7.1.5, but seems like the the framework is being implemented slowly in preparation for it (Strings, removal of cap). Removing the cap is the first step in the right direction imo. I personally run 2 accounts on tokens, but I also play a lot of hearthstone, with that setup, a cap forces me to cough up real money. 36 tokens in 2 years means you have to pay 6 months for your 2nd account, and leaves no room for hearthstone.
Maximum of 10 unused tokens in your bag is still enforced however.