I think it would be interesting if there is a Prequel to Elder Scrolls set before the events of Arena which would explore how the world was like during the "Dawn Era" or "First Era" or "Merethic Era" or something, Of course exploring what the Dwarves were like before they disappeared.

I would love that, but it isn't high on my priority list
I'd like to get some more answers on current events before going back in time.

Example of what events you would like to see? Playing in a Dwemer setting would be cool, but that is not a goal in itself. TES games need an epic goal to fight against And since Nirn's past lore is already pretty much set in stone it must be something that has already happened, alternatively some huge event that has so far been undiscovered. The overthrow of the Camoran Usurper would be neat to take part in. Or the Alessian wars... Your ideas?

Part of what makes The Elder Scolls so intriguing is that there is a lot of history and enigma in Tamriel. If Bethesda made a game taking place during those historic events, they would no longer be history or mysterious, they would just be current-events.

What I would like to see in future Elder Scrolls games is more history being examined. Not just in books, but perhaps exploring historical places that are not just dungeons for looting. Morrowind did a good job with some of the Dwarven ruins, and actually made their disappearance intriguing. Otherwise, few people would actually care.

Redguard was technically a prequel, taking place in the late 2nd era.