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No, every shapechanger (tag) in the MM leaves Type unchanged. The example creatures are therefore not affected by humanoid-targeting spells.

"Statistic," as a defined term, is spelled out on MM pp.6-11. The second element spelled out is "Type," of which both Celestial/Giant and Humanoid are instances. So which stays?

The Coautl's and Deva's shapechange abilities specify that they retain their statistics except for a few callouts which do not include Type. Since their Celestial Type is a statistic they retain it and are still Celestial while in humanoid form.

The Oni's shapechange ability specifies that the only statistic to change is Size. Since Type does not change, the Oni is still Giant while in humanoid form.

For completeness, the Quasit, Yochlol, Imp, Doppelganger, various weres, Mimic, Slaadi, Incubus/Succubus, Vampire, and various Yuan-ti are the other shapechangers in the MM. All shapechange with similar verbiage to one of the samples above, and so all retain their type.

Bonus: some Change Shape without being shapechangers!

Metallic Dragons' Change Shape ability does change type. Night Hags' and Lizardfolk Shamans' Change Shape ability doesn't change their type.