BLW signs of readiness

Hey ladies, I have a question. I follow two different BLW groups in FB. One has signs of readiness that include baby sitting unassisted and is therefore ready for solids. And the other states that baby doesn’t need to sit unassisted but just has to be able to sit in a high chair. Per their pediatricians, there are conflicting opinions and some peds didn’t even mention sitting un/assisted and to start purées prior to 6 months. CDC and WHO say unassisted.

So my question is does baby need to be sitting unassisted? What does your peds think?

Thank you ladies!