I actually teach an online grandparents course, though not one featured by the Guardian, alas. The focus of the course is not to "teach" people "how to be grandparents" or "how to look after babies". I sat in on a course that did that once and it was utter rubbish and super patronising.
Instead I focus on the research which has emerged in the past 30 years about infant development, the microbiome, brain development, the ingredients in formula and breastmilk, supporting parents' feeding choices, weaning, allergies...loads of stuff really and we often end up discussing how to manage changes in family relationships and dynamics.
The people who come on my course are intellectually curious and above all aware that things do not remain the same in any field. They certainly do not think my course is "ridiculous", @Nanna8! They are always a pleasure to meet, and running the sessions is the high point of my month as I get to meet such interesting people albeit on a Zoom call. I always follow up with a bulging online information pack of links to reputable resources, research, videos etc etc.