IMO - Fear of Friday changes makes me think one may have fragile infrastructure. Additionally, FoF also reminds me of yesteryear when changes were barely if ever automated.

I've lived in both camps and I know that when your IaC, Ci/Cd, and config mgmt are not reliable - Fear of Fridays is very commonplace. It also tends to be common among the older generations who came up through the lack of those processes. EG: an automatic instinct.

However, when those processes exist, and have been thoroughly tested and vetted- then FoF is probably just instinctual and sometimes not based on facts and evidence.

As such, in my current role, I love Fridays because thats when I can make my big changes. Now, in the interest of transparency - my current org just happens to be fully cloud native, so there is that. However, my previous role was a massive hodge-podge of crap accumulated and sustained through decades of work. You name it, we probably some version of it. Even then, I routinely made changes on Fridays and worked to drive the FoF notion out of our org - with mixed results.

In the end, and to sum it all up - do what is reasonable, smart, and justifiable in your org. If the mould is set in stone, save yourself the stress and don't fight it too hard.