I don't believe that is true.

Either last year or the year before (maybe both years, they're blurring now) I transfered some shares from my Webroker account to my TD TFSA and incurred a capital gain on the transfer and ended up paying capital gains on it. So, I would assume it would be similar if you transfer at a loss you could claim the capital loss.

The way my accountant put it CRA sees it as you selling at the market that day (you can take the high or the low for the day you perform the transfer) and then buying in your TFSA for the same amount.

That's my experience, I'm no tax expert.