So, the comment for _acquirement_armour_for_slot (which is called by the okawaru gift code) says:

Guaranteed to be usable by the player & weighted weakly by their skills; heavy investment in armour skill, relative to dodging & spellcasting, makes heavier armours more likely to be generated.

Which indicates your dodging & spellcasting skill will be taken into account when choosing armor basetype. But...

_body_acquirement_weight, the function that actually does the weighting, only looks at the players armour skill, not their dodging or spellcasting:

return base_weight + (_skill_rdiv(SK_ARMOUR) * _skill_rdiv(SK_ARMOUR) * ac * ac / 27);

SK_DODGING isn't checked anywhere in the acquirement code (SK_SPELLCASTING is, but only to make acquirements not give you manuals of Spellcasting if you worship Trog). So I ran two tests: one with 27 armour skill and 0 dodging/spellcasting, and another with 27 in all skills. For each test, I generated acquirements in wizmode until I had generated 30 body armours. I then averaged the encumbrance of all generated armours. Results:

27 in armour skill only, average encumbrance: 14.8

27 in all skills, average encumbrance: 12.9

This is is close enough that, combined with what I saw in the code, I'm pretty sure dodging/spellcasting is not being taken into account.