Tracking is not a requirement to get "Global TRS" and the 20% discount that goes with it. You do have to meet all the other standards and requirements though.
Tracking is not a requirement to get the US TRS discount (20%), but tracking is required on at least 90% of all shipments to get the Top Rated Plus designation, along with what eBay says is better placement and visibility in searches, etc. And of course you have to meet all the other parameters for TRS+ as well.
The key for US TRS+ is not what shipping services you show on your listings, but which shipping services are actually used to send parcels to the U.S. So you can show whatever you wish for shipping to Canada and to the U.S., but 90% of what you actually ship to buyers in the U.S. must have tracking if you want them to qualify. So, for example, I sometimes upgrade a buyer's shipping (free to them) in order to get tracking even if the buyer has only paid for the Small Packet (non-tracked) shipping shown in my listing.
In my opinion you have to very carefully analyze whether the TRS+ designation is worthwhile going after for a Canadian seller. Remember that the US TRS requirements are based on US transactions only. So for example, you may have 300 transactions in a 12-month period, but if only 75 of those were to the US, you won't qualify even if you used tracking 100% of the time.
The vast majority of my buyers are in the US and I sell quite a number of moderate to higher-priced items, so it's worth it to me to get the exposure, but may not be if a large part of your business goes to Canadians (or internationally) and/or you're selling items of lower value that aren't worth paying tracked shipping on.
In other words, unless you know the (purported) better exposure on .com is really going to do you any good, and unless you know you can take advantage of it with enough listings to generate increased sales, you're probably better off just aiming for Global TRS and getting the 20% discount.
