Last year WJ flights to CDG were punctual as they were WJ 1st year direct flights from YYC to CDG.
This year SNCF ticket prices are totally out of control unlike past years rates do not start low 3 moths before departure increased to departure date but rather now rates are randomly by a bunch of monkeys roaming in SNCF office. However, if you book your train to Germany but for some reason like Corona or construction your train will be cancelled or even at times SNCF allows ticket changes to refunds due to for example possible strikes then you have choices of refund, change trip, delay, etc. without paying service penalty fees. On your cell phone SNCF app enter your SNCF ticket # or code and it automatically adds alerts sent to you one day before departure at about 17h00 (Paris time) if train encounters delay or cancellation...etc. and then SMS you your platform number before departure, and if en route you need to transfer to another train the app SMS your next train voie number and whether delayed or not...etc. The SNCF app has many features to report instantaneously your concerns to operators that can guide you through.

See also:
Trainline Europe
Europe train tickets in advance: Yes, here's how to save
Rail Europe
Man in Seat 61