Just assume that COVID test results are required for hotel check-in and schedule the tests accordingly (add a few hours for flight delay).

I am going a bit crazed as I have a 21 hour transit in Lis coming from RAK and going to NY. Everyday things change. i really wish US citizens can get some sort of digital form of the CDC card so we don’t have to worry if our CDC card will be accepted or not.

There are places where you can get a EU DCC, such as France, and Switzerland has arrangements too. In your case I would assume you simply need to get either a PCR or antigen test for transitting LIS, which you will need anyway for the USA too. But as things stand CDC cards don't get you off the testing requirement, so the changes this week haven't changed anything. I imagine CDC cards will be allowed at some point, but that may be a few weeks off yet. Ironically Morocco has joined the EU DCC scheme so if you had got your jabs in Morocco then you would be let off the testing requirements.

I just emailed my hotels in Lisbon and Porto, and both confirmed that I can check in with either the US CDC card OR a negative covid test result (PCR within 72 hours or rapid antigen within 24 hours).

Well my trip is two days away and it looks like I'm going to be stuck getting a Covid test before flying. I just want to double check that as long as I get a rapid test the day before I fly I'm good? The entry requirements technically say 24 hours before boarding but I'm assuming as long as it's sometime the day before all is well.

I was close to the airport (yyz) yesterday evening I knew there was a TAP flight scheduled so I made a pit stop to get clarification on a few things,

Ontario Vax certificate is no longer recognized by Portugal, therefore a Covid test is required again ( Antigen is accepted)
They we’re allowing non Portuguese citizens to board as they claimed they are not enforcing the “Essential” travel regs
so I ‘m also flying to Lis tomorrow and had to book my Antigen for tomorrow morn.

It is indeed 24 hours under the rules, for antigen, unlike the USA restriction which is the day before and could be 47 hours in extreme cases. This is where if you want no hassle you better stick to the 24 hours, so if it's an evening departure then you may find it better to do the test on the morning of departure. There again the agent may just check the date and not check the time - but that's just a risk. PCR remains 72 hours, so that gives you more leeway. In a European context getting an antigen lateral flow test is easy - they are available almost everywhere and a 24 hour restriction would be easy to fulfill. In North America not so much.

Morning Antigen test on the day of travel (evening flight) is preferred because one may need the testing results for hotel checkin.

Great, that's going to prove difficult to find for me today. And I can't do it on arrival right?

Hotel check-in is not a problem, I'm only transiting through Portugal.

There was a provision for testing on arrival in LIS, but it was changed after the system got overloaded. It's only used now if someone is caught untested in LIS, and with it comes a hefty personal fine as well as a fine for the airline. Hence why TAP knows to check these things. Your better bet may be to get a PCR test with a short delivery time for results, some test kits can be done in a few hours. Lateral flow antigen tests cannot take more than 40 minutes or someone is doing someting wrong.

Airlines would not let you board the plane without Antigen test results. Once deplane, there are ~5 people checking vaccine and rest results before you reach immigration.
So, you need to get a test.

I took 2 different rapid tests yesterday and I'm actually not sure either one has the required information on it. These requirements are just crazy, I'm truly worried about being denied boarding to my flight.

If you want to share the specific details, or point to the websites of the providers, I'm certainly willing to give an opinion. Most people find one test is OK.

I had a suspicion that the apparent requrement for Canadian travellers to be on Essential reasons for travel was some mistake or oversight. So I'm not surprised it was ignored, and while certain things are carefully checked upon arrival in LIS, this was not one of them. But the good news is that there is confirmation, via the website of the Portuguese Embassy in Canada, that non essential travel is definitely allowed. My reading of the vaccination certification process is that aspect is still in place, so travellers from Canada will need either a lateral flow / Antigen test certificate under 24 hours before departure, or a PCR test certificate under 3 days old.

I have a trip to Europe in the first half of April (4/1-4/15). I am a US citizen, resident in the US and I'll be transiting but not staying in Portugal flying TAP. I currently hold a Swiss digital vaccine certificate with a 270-day validity through May 15. My understanding as far as transiting Portugal under the current rules (always subject to change of course) is that I should be good to go without a pre-departure test. Is that correct?