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.
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.