The answer is yes, to add tricks. The tricks are available to mages that take one of the Spell Conversion feats in chapter 2 (pages 106 and 107 of the first printing, not sure if that's the same in the second).
Another answer is that the Spell Point advancement is linear, and there's no reason NOT to give the mages their spell points. It would look odd to have 0, 0, 6, 8, etc. and could potentially screw up a multi-classed spellcaster (even more than multi-classing normally does).