And that all assumes of course that the panel physicians will be able to accommodate scheduling people within that 30 day window,
Tend to agree. We booked our medical in Canada and had to wait 6 weeks for the appointment. This may prove to be a bit of an encumberance on the application processing times.
Playing devils advocate (please, be gentle), there are a few thing, that to me seem to be placing the onus entirely on the applicant(s) that could push total processing beyond the 12 month proposal.
my interest is if they will process old applicant's faster in accordance of this new law
This is not a law. It's a process/procedural change. You won't be able to use that against them if they don't meet the expectation. There really is no guarantee that things will improve. The 80% in 12 month are simply metrics they use to measure their internal performance. Until the end of next year, it will be difficult to confirm if they met the target (and I suspect with all the changes they won't). Keep in mind, they are only promising to process the application as well, not necessarily approve it.
Moving to one generic application is a good idea, but given the specific nature of some of the current regional requirements, is everyone now going to have to comply with them. To me it only makes sense to use the most stringent requirements for everyone. This puts a great deal of additional cost and effort on the applicant that weren't in place before (i.e. DNA testing, labour history, certified identity documents, etc).
External processes (medical/police certificates) being requested once the process starts could be another delay, not of IRCC making, that can delay your application. Particularly for those in Canada. Going back to your home country, or applying to an embassy to get a PCC is a pain. Been there, done that.
I think that they have, in essence, moved a lot of the administrative and documentation issues that delay applications onto the applicant to do up front. The processing times from IRCC should improve, but the due diligence on the applicant (and the time they spend preparing) will increase. And they have left themselves some decent caveats to allow them to deflect any delays.