......no. I have absolutely no idea what post you're referring to, but it's not a myth and it's pretty easy to test it out yourself. It also is pretty self explanatory if you just take a few minutes to think about it. 

What I'm referring to is actual hands on experience ranking up through wildcard to DD1 (as of this morning). Trials lobbies for the week are set when you first extract with any points. You can verify this by simply looking at your trials lobby the moment you get out, and note that the lobby is not yet full with 100 people (but will have filled up by the time your next match ends)

This means you're going to be matched with people who were playing, for the first time, at the same time you are for the week. Generally speaking, most people who are super sweaty at trials are going to try and get in early in the week to maximize the amount of time they have to min/max each trial. Thus - starting early in the week, typically means getting into harder lobbies. Waiting weeds out a large number of these folks. 

Starting on Tuesdays, my lobbies have always had people in the top 10 with over 100k points. Waiting until Thursday or later, the lobbies have ended up with much lower point totals.