I can't open the link but I suspect that this is the article that has been floating around on FB AI groups. As @afraser has said, just because something sounds researched, doesn't necessarily mean that it is authoritative so, if you're concerned about something, ask your onc.
While most of this is either commonsense or continuing a general push for healthier habits (ie beware alcohol and nicotine) it should be noted that the author has no medical qualifications and is not a dietician. She has had cancer and may well be genuinely motivated towards helping others but your own oncologist may be worth talking to before making any significant changes.