They were already allowed to sell service over the fibre networks, the problem was that the CRTC regulated wholesale prices they'd have had to pay in order to do so were higher than the retail prices charged to residential customers by Bell.

The new and improved CRTC regulated wholesale prices are something like 50% lower than the previous ones iirc, but still higher than the retail prices charged by Bell.

This is disappointing, but not exactly surprising. They've been doing a bad job of it since 2006 and continue to do so. The independent ISP market is already 95% gone. This is both too little and too late. The problem seems to be too complicated for politicians to understand, and the regulatory capture too thorough for any well-meaning bureaucrats trapped in the system to overcome.