There are significant penalties for getting it wrong on a contribution; but I believe that it is proper to be placed into registered accounts (including TFSAs). This was gone over ad nauseam a number of years ago with legal opinions provided and I have placed mine in a TFSA.

it is totally unrealistic to ask for it to be written into the TFSA rules as a legal opinion is all that can be asked for and approaching CRA is totally unrealistic (besides being beyond the Staff at CRA who are not allowed to voice opinions since they are not sufficiently knowledgeable to voice any) and if your broker is comfortable placing it into a TFSA then my suggestion is that you have all that you can get