Can you sub a soy or almond plant milk here?

You know, there are versions that use either types- and you can certainly try it out to see if you like the results. Non-dairy milks have slightly different compositions- in terms of sugars, fats, and water content, and may or may not leave you with a cake that is dryer and less unctuous. Given your options I would recommend using the soy milk, which is closest to the composition of whole milk. The flavorings should cover any potential "beany" taste of the soy. I'm not sure what exact function the milk is playing in the recipe, but I'm sure it's a combo of providing fat and protein, as well as liquid to activate the gluten in the flour, as well as sugars that will contribute the the browning you want in the final product.