they are not unheard of, just considered rumours, because of the lack of actually df users in east blue
Literally the third most notorious active pirate in East Blue at the beginning of the series has a devil fruit. Also the Marine Captain of Loguetown, probably the most important island in East Blue, has a Logia.
and the information service is not for the public, again do you read? cp serves the wg not the common people.
Who is talking about Cipher Pol? The World Economy newspaper reaches every backwater hovel. Dadan manages to get a newspaper while living up a mountain, in a jungle, behind the backwater of a backwater.
Literally everybody gets the global news.
finally all the big hitters are in the grandline/new world where people know about dfs and consider them real.
The heavy hitters in
every sea have devil fruits.
Bege from West Blue, devil fruit.
Kidd and Bonney from South Blue, devil fruits.
Law, Drake and Hawkins from North Blue, devil fruits.
Luffy and Buggy from East Blue, devil fruits.
its in the east blue where peopel doubt thier existence where they dont actually interact them with much if at all and when they do they dont for long, let me give a quick example:
luffy went through shells town, baratie, louge town and then dipped to the grandline, now, how many people saw him, lets say a few hundred, those from shells town will now believe in dfs untill the kids grow up and it become a rumour again, and other islands will consider them a rumour
All this gets immediately undermined by a global news service that delivers to every island, that informs people of the fact that 99% of famous folk in the world, have a devil fruit.
Imagine what kind of tard you'd have to be to look at the news, see that nearly everybody of note has a superpower and go "Naw, nobody on Craggy Island has those powers. Fake news!"
Freakin Johnny and Yosaku knew of the Warlords. News clearly gets everywhere.
The easiest way to explain devil fruit ignorance at the beginning of the series is either:
1) It was for the reader's benefit, to treat devil fruits as mysterious objects that needed explanation before quickly treating them as mundane.
2) Oda changed his mind and wanted them to be far more common than he initially planned.