Keep in mind that as of right now, the only lines that have enough infrastructure in place to support better than an hourly service are the Lakeshore Lines and Kitchener to Mount Pleasant (-ish). Work on the Barrie and Stouffville Lines is ongoing, but still a ways away from being ready for lower headways, with Stouffville being the closer of the two.
But also bear in mind that ridership is still well below where it was at this point 2 years ago.
There are currently scheduled to be a large round of service improvements/restorations this coming September. It doesn't sound like it is going to be quite the full reinstatement of service, but it does sound like a lot of the off-peak service is coming back.
Dan