I have not seen such an assertion nor would I believe it if I did. I just read his short story "Z is for Zombie". I suspect his personality gave him the insight to craft the pithy, incisive narratives we love to read. So boo, hiss to jealous mediocre writers of crap obits.

Sad that he is gone, but none of us last forever.

Of course a writer's personality comes out in their writing, that is what makes it unique.
Ellison was a powerful incisive writer, some times abrasive, but always original, which is what made him unpopular with other writers.
When questioned about why he was so litigious his answer was that if people tried to pick his pocket they ought to be prepared to find a mouse trap in there.
It is one thing to claim influence but some do take it to far, the famous example being "Soldier" Ellison's story (and outer limits episode) of a warrior from the future being thrown back in time to stop his enemy from altering history, falling in love fathering the cause of the war, was so obviously the part basis for "the Terminator" (the other part being D F Jones' Colossus, the story of a sentient computer design to defend America deciding that humans were to dangerous to themselves to be allowed freedom).
It would have been easy enough for Cameron to admit this and thank Ellison and Jones, but did not in such circumstances Ellison was right to sue.

Harlan Ellison will be missed, but his works undeniably have been along with those of Philip K Dicks the basis of a Sci-Fi literary revolution and for that we should all be grateful.

My favourite "grumpy" Harlan story was when he was invited to participate in a writers meeting to help develop the plot for the very first Star Trek Movie in the late seventies.
Roddenberry kept rejecting ideas and demanding "Think Bigger, I want this to be really Big!"
After an hour or so of this, and Roddenberry pooh poohing ideas from DC Fontana and EC "DOC" Smith and others of that ilk Ellison stood up and with huge dramatic flare declared
"The Enterprise is testing out a new type of engine, one that transcends warp drive, one that breaks one barrier after another, takes the ship past light speed, beyond tachyonic, past even the speed of thought and mind until finally at the very center of the universe the Enterprise breaks through the final reality barrier, enters the world of spirit and finds itself staring in to the very face of God Himself!"
Slamming his palms down on the desk Harlan and Gene locked eyes.
Then Gene said, "No Harlan, you don't get it, I want something BIG!"

Harlan turned to leave but Roddenberry screamed after him
"Who the hell do you think you are?"
To which Ellison apparently replied "I think I am a writer, I don't know what the fuck you are!"

In light of Star Trek 5 it might be noted that Bill Shattner was also at the meeting.