I wouldn’t worry about that story, personally. I saw it last weekend — it seems to have come from one source and spread virally to a bunch of conspiracy sites. Plus the policy change in question was in Nov 2013, not recently.
I’m betting that either (a) they don’t want to keep large amounts of cash on hand at all branches or (b) they’re catching flak over money-laundering accusations and want to play the good guy for a while.
Also, HSBC plc stock has been trading in the 52-57 range (40-60 the last four years) for the past year. While it’s at the low end of the 1-year range now, its behaviour doesn’t indicate people with inside information looking to get out of Dodge.
This looks more like a poor attempt at stock manipulation than a genuine issue, but I could be wrong.