Denty225 found the following on the Warframe website . . .

A little heads up guys. I was reading the hot topics on warframe forum and saw the devs are considering removing buffs from the alternative helmet skins. This could mean that any helm blueprints you have waiting to build may lose its buff. If you’ve already built it you will keep the added buff.

Time to start forging those helms you’ve not got the Warframe for yet!