It is easier to just use the frase “recommended” and trust that the reader understands the meaning of that word, instead of explaining in detail “why and when” because that would be needed.
But in that case a “newbie” would not understand it and skip it eitherway. 
That only applies to the default bootloader in the ESP i mentioned.
M$ should not interfere with other bootloaders that are installed in the ESP under their own vendor dir, else M$ would be violating it’s own UEFI specs. 
It (M$) does however tend to fiddle with the boot-order and default selected boot entry, which can be fixed easily in many ways including the BIOS itself.
Still wrong as i explained above about the ESP.
Eg. not advisable but possible because it is needless.
PS: You probably have MBR+GPT
(Don’t mix partition-table types and BIOS types)