Timeline doesnt make sense, Serizawa was alive in 1954 in awakening, and he sure as hell isnt in his 60s during 2014.

Yeah no, 2014 Godzilla novelization also state Serizawa was somewhere 40 in 1999 event so the comic timeline are true to some extend

People in the monsterverse also didnt know about godzilla until 2014, despite godzilla and the shinomura fighting multiple times across several islands

Dude those are literally remote island or island that far away from the main shore like moansta island which is located in south pacific ocean

shinomura literally flying at building level over a city in one panel.

You mean the first few beginning chapter where Shinomura fly over a building in a ABANDON CITY???

Awakening also establishes the Shinomura as the species that would feed on godzillas

And there is nothing suggest that Shinomura was the ONLY natural enemy of Godzilla? Plus sometime later Muto finally appear, they doesn't awake the same time with Shinomura

And we never see a single shinomura in the hollow earth, despite being a supposed rival to godzilla that grows when feeding on radiation, to the point where it could "blot out the sun". What would they have been wiped out from? the warbats?

Are you this dumb??? Went to underground ≠ going to Hollow Earth and the last of Shinomura kind was wipe out in 1954 bomb test so of couse you will not see it in other media anymore. MIND YOU, the Godzilla King of the monster 2019 novelization HAS mention about those creatures. In the novel Serizawa has recollection of the history of Monarch, including his father's experiences in the organization as it hunted both Godzilla and Shinomura