Are you saying that without the clarification, readers might be confused by what's implied by "man" here?
Do we have to add this everywhere we use the term "man" now?
No; the journal article made the clarification because it was intentionally using the incorrect, not widely-understood definition ("people with a Y chromosome") for brevity. This group includes cis men, trans women, and — perhaps most surprisingly — XY people born intersex with "enough" feminine primary sexual characteristics at birth that they were then assigned to be female through genital surgery and lifelong estrogen injections. You might grow up all your life as female, and yet be more prone to these cancers, because you happen to have a Y chromosome — i.e. because you are "a man", in the chosen terminology of the paper. This is not how the word "man" is normally used!
Without context? Literally, never.
The term “man” is understood by a very broad swath of society, and overwhelmingly the educated class who writes for and reads these journals, to refer to the gender construct, not the biological fact. Clarity is always better.