Zach also shared a statement from Emmys bosses, in which they said they "cannot ensure any particular individual is included".
Their message read: "Those involved in the In Memoriam selection process are very aware of the sad passing of Mr. Cordero due to coronavirus and we assure her that his name has been given every consideration for inclusion."
"With so many people passing in any given year, we simply cannot ensure any particular individual is included, nor do we release the names of those included prior to the telecast."
Zach also blasted the awards ceremony for leaving out his 'Scrubs' co-star Sam Lloyd, who died earlier this year after suffering a brain tumour.
In a separate tweet, he added: "I should mention too, that they also left out Sam Lloyd. I would have never even considered 'campaigning' for Sam because he had more TV credits than most actors I know."
The In Memoriam segment also didn't include basketball star Kobe Bryant - who died in a tragic helicopter crash in January - despite the show being held in the Los Angeles Lakers' home court.
However, the tribute - which featured a moving performance from H.E.R. - did honour the memory of Dame Diana Rigg, Chadwick Boseman, Naya Rivera, Carl Reiner, and others who passed away in 2020.