The Definition of advice is congruent with recommending and providing guidance. It doesn't necessarily state that has to be concrete evidence.
And, Absolutely you can give advice, it doesn't necessarily mean you have to be right or wrong. That's the point of discussion, am I right? I challenge you to read through any of these other threads, you will find a litany of members offering opinions, insight, and feedback that may not necessarily be 100% accurate, but that's not the point, it's the point that they're offering their opinion based off what they have knowledge of to the best of their ability.
Not every answer has to be definitive and accurate. That's what discussions are for and feedback. Many times, forum members might post something they believe that might be accurate, with all likeliness it wasn't and another forum member will either correct them or advise of their differential of opinion.
And just to reassure you, My advice was entirely accurate what I posted.
So... no. Got it.