Yaarel
🇮🇱 🇺🇦 He-Mage
When Sage Advice describes the designers intent, that is nonidentical with the rules-as-written.Not always. Sometimes it's chosen for you. Druids are a good example of that. We know for 100% certain that they have the taboo that they will not wear metal armor. The designers have said this straight out. People can come up with all the excuses and justifications they want for how it's not really a taboo in 5e, but none of those can overturn the undeniable fact that is spelled out explicitly in the Sage Advice, which is talking directly about the "will not wear metal armor" quote in the PHB.
In any case, mechanically, the Druid lacks metal armor. So is prescribed in this way.
Whether that is understood as a "taboo" can be a player decision relating to an Ideal (unity with animals) or Flaw (superstition that one is hesitant to overcome), or to ignore it as one feature that other features elsewhere can augment.