They made it very clear last year, that they will NO LONGER be "Flexible" with the limits, and offer any SONs by any "appeal" processes. Otherwise, what is the point of even putting a limit?
It sucks, but they made it very clear where they want people going into, and that is mostly FM.
Even last year, people did NOT get SONs for IM(and maybe 1-2 other specialties, but dont have the file open infront of me), and had to re-apply this year.
It absolutely sucks, but it is an expected outcome of their decision process.
Your best bet is call your program director ASAP, explain the situation, and see if they will delay your start date and sponsor H1B. If you are an IMG (non US grad), you need STEP 3 done before you can get H1B. Explain the situation clearly.
IF you are a Canadian at a USMD/USDO program, and didn't get SON for J1, apply for OPTI ASAP(if you havent already done so). You can do your PGY1 on that visa(sorry carribeans, aussie, ireland, only US graduates can back up with this visa). Then you can re-apply for SON J1 next year, and make absolutely sure you are submitted at X:00:00 time stamp. Or hopefully your program may consider sponsoring H1B also. Be creative, some people have offered to put towards their educational stipend amounts towards the costs etc...(just dont go advertising this, as it may not be "allowed").
It is a ****ty process, but it seems they are being firm with things, and this was already the scenario last year..and they made it abundantly clear that would be the norm moving forward. As well they published the cut-offs for each specialty early also.
Lastly: IF you have an alternative citizenship other than Canada, it would be very useful to look into the specifics of using that to get a J1 instead...and how that all would pertain re: ECFMG etc etc. There may be ways to make that work for the lucky few who do have that option. Or marry a US citizen, easier said then done.
It is getting harder and harder for IMGs and it will only get worse. For future students reading and considering foreign programs, make sure you know the ins-and-outs of the process before you commit to it. Be sure you are comfortable with the level of risk.
Those who didn't get a SON this year, may very well get it next year, or find alternative path outside of the J1(H1B, marriage etc).