I really, really doubt that. They pulled back on “patriotic education” which is honestly something a relatively large minority cared strongly about. If they tried to phase out Cantonese everyone who didn't move from the mainland would go ape. Also, Mandarin isn't even an official language, Cantonese and English are it.

Matthewrudy is right. The legislation for regulating Cantonese in broadcast and print media was enacted in Guangzhou, not Hong Kong. My mistake.

No politicians would say outright that they want to eliminate a major language, but they could drastically reduce its usage by imposing specific restrictions. And not just on spoken Cantonese, but variations of written Chinese other than the official simplified characters.

I wish I could post an original article here with more details, but for some reason even the bilingual news sites don't cover this story in English. Wikipedia gives a pretty good summary: http://en.wikipedia.org/wiki/2012_Anti-Cantonese_regulations. The sources are all in Chinese (the only English link appears to be dead) but Google's translations weren't too bad.

They did this in Guangzhou, where the local TV channel switching from 100% cantonese, to 50% cantonese.

Mandarin use has increased in Hong Kong in recent years, but for economic reasons, as mainland visitors and businesses have flooded our small city.

Doubtful - last I checked they were trying to shift the financial center from Hong Kong to Shanghai.