I had to wean mine at 8months, and basically failed

. She ended up having a milk trial that she passed though.
You can get proper flavour modules for neocate for babies/ toddlers over the age of 2 because of the taste issue. Over here they are on prescription just like the milk is. Not sure about other makes though.
At this age food can carry him through while you transition him iyswim? So the intake may be too low for a few weeks, but should pick up as he gets used to it.
Is soy an issue as well? Some doctors are happy from age 1 for boys to have soy, and there are age w more options then, including yoghurts and cheese to improve dairy intake.