40 TPH is an industry standard for a purpose built automated metro so no one should be skeptical in the first place about the Ontario Line.
It may have been an exaggeration to say Line5 could be retrofitted for such operation but they should be able to run at least 34 TPH if not 36+ TPH with platform screen doors. There are numerous low floor platforms with more doors per side, including the 40m configuration of our current trains.
Calgary is purchasing CAF Urbos 3 trainsets with a "double-door" configuration