I have found things to be just the opposite of what you are saying.
I don't have a ThankYou account but I have called the ThankYou Call Center upwards of 5 times in regards to this deal.
Here's how it went each time;
Dial tel:1-800-842-6596
Hit "2" on dial pad to discusss ThankYou Rewards pprogram and redeem points.
Hit "1" for English.
Hit "#" if you do not have ThankYou account number available.
Hit "4" to speak with a ThankYou associate.
Then I usually talk about ThankYou program and follow up with questions about Airline Transfer Options.
Everyone I have spoken with has said the BA and SQ will be available sometime in April.
Most recently they have actually tried to walk me through the "Exchange" process. Not knowing I don't have an ThankYou account.
Then I thank them for their help and wish them a pleasant day.
That's it.