I'm not sure that is entirely the case.
It doesn't make sense for Q to "stress test anons." The very nature of the board makes it rather silly to use that.
While the people pushing that narrative do have a point - that people reacted rather foolishly at times - that is nothing new and also rather predictable when it comes to the chans.
There are a few ways to take the "stress test failed" remark, one of which is simply that anons overwhelmed whatever system was being tested. While this also seems silly to announce - it does make some sense if you figure that 8chan is a pre-positioned asset to be used as a comms hub in the event of internet censorship getting out of hand.
It may not have been a stress test of the servers hosting infinity, but a test of servers responsible for somehow defeating the attempts to block 8chan routing in certain countries.
I think to take off with much of anything Q says in a direct manner is a bit of a silly thing. Q is a bit of an oracle, and pretending as though you have the true meaning of what Q said is probably going to bite you in the ass.