A leading question is only a problem when the lead prompts a person to answer, not with the information that they think is correct, but with information that they think the asker wants to hear or with information that they are predisposed to provide based on how the question is posed.
It would be a problem, for example, if a prosecutor asked a witness a leading question during a trial, as it's the witness's honest recollections that are of interest in that exchange.
This is not an issue for questions with clear, objective answers which can be externally referenced. So in your example I would say that you would not be asking a leading question if you used the second formulation.
If P&L stood for "Pumpkins and Lattes", your company's two major revenue sources during the year, it's very unlikely that you would get a different answer in either form of the question (and venturing a guess about Profit and Loss would make you look even less informed, as you not only didn't know but actively believed something incorrect).
If you really want to ask the most open-ended question possible without seeming ignorant you'll have a narrow line to walk. I recommend hedging in a way that makes it clear you have a suspicion of what is correct and just want to verify:
And, just to double check, what does P&L stand for in this usage?
Could you confirm for me what P&L stands for?
Asking a question frequently implies that you don't know the answer, or are not confident in your knowledge. Hazarding a guess suggests that you might know but are unsure. I don't know that you can provide zero information beyond your lack of certain knowledge while also giving the impression that you have more than zero knowledge.