Why not just call it Birth Preferences, rather than Plan.
Takes away the whole problem which is just about semantics really. Birth will be as it is, often, yes, but medical professionals will do what they do the way they usually do it if they don't know your preference - and something really easily avoided or rectified can make a huge difference to your experience depending on what you want. And lots of things it's worth having there just avoid you saying it/having to think about it at the time.
For example, if you don't specifically decline it, someone will jab a needle into your thigh as the baby emerges. You may not notice, considering, but they'll do it, and if you don't want it, there's not a lot of mental capacity left over to say, 'oh wait, there, baby, just hang on a sec and stop that crowning whilst I chat to this MW about the pros and cons of this for a second....'
And then the baby emerges and the MW announces the sex when you wanted DH to. And then they put it on your chest all icky when that's your worst nightmare, or they take it away when you want skin to skin, and someone else is chatting to you about the placenta and trying to tell you if you've torn and the baby is screeching and your DH is crying someone is mucking with cord and scissors and PHEW. Just having a nice little list, in advance .... preferences for treatment. Not 'this is how my birth will go!'