Hi Peter
I think there is a very good chance that Frederick did see his son, but the son would have been too young to remember. Here is his medal index card, and the clues are in the information that is not given.

He did not receive either the 1914 Star or the 1914-1915 Star and therefore he did not leave the UK until 1916 or later.
You could wait for Ancestry to publish WW1 Service Records for surnames beginning “M”, and hope that his papers survive. In the meantime, if you get no joy here you could ask on the Great War Forum in the hope that an ACC expert can tell you when the number 21469 was allocated. I would put "Army Cyclist Corps" in the question title to attract the right audience.
Ken