Don't listen to these experts who post videos on YouTube and say they know the truth. No one knows what will happen next. I think now is a good time to decide whether you want to invest in Bitcoin or not.
I don't get my investment advice from external sources, but this is because I know how to trade and invest rightly myself. But what about those who do not know it and still want to participate? That's why I see your advice as bad. For trading, yes, one should be wary of these people unless they are teaching you how to trade. This is not hurting anyone as far as I know, only that I advise everyone to be careful and not believe that they can get to make money in trading so easily. I learned from the external sources too and there are many, and it would have been bad for me if I had disregarded all of them by then for the belief that they are all bad.
But for investment, those videos and Tweets and others could be a very good one, and there are some friends that come to me for investment advice having seen it on social media. They could have entirely missed out on this if they disregard it entirely, so one should still learn through them or continue to let what they post online be what gets them informed as this information is certainly not hurtful, and even better if one does their own research before using them.
And for Bitcoin investment, every time is the right time to invest in Bitcoin if the bull run has not happened yet. As it is now, the bull run is still being expected so no one would lose their money investing now. However, for the right price, my advice is for the person to DCA as the best price has already been missed and can't be recovered anymore till the bull run happens.