The PM promo was actually for all provinces. You had to change plan to get it after you activated with PM. But that was $45 4GB unlimited province only (not canada-wide). This is not as good as the previous promo $38 4GB
AB only deal, and it's a market dump. Public Mobile is offering it, now Bell/Rogers are competing in TELUS's home province AB to steal customers from TELUS/Koodo in TELUS's home province.
TELUS has a market advantage in AB as it's their home province (lower overall costs because all incubent fiber whether wireline or wireless is TELUS), and they're known to offer such province wide talk deals via Public Mobile to attract that last mile of customers who only go prepaid or will quickly jump ship over this kind of deal outside of SK/MB/QC.
This upsets Rogers and Bell who could potentially lose customers on their subsidiaries, and choose to only attack TELUS/Koodo/Public in AB, to hurt TELUS's margins.
Jump ship if you're in AB and you prefer to go with Virgin or Fido. Different advantages with different carriers.