Seriously, I mean just look at the evidence!
- Similar style of jacket to Liquid's iconic look in MGS.
- A very Big Boss/Solid Snake-esque mullet he's rocking there.
- Also, blonde.
- His tagline during the trailer he's shown in is "A Youth who Curses his Fate", which fits into Liquid's philosophy or whatever about being a slave to one's genes, and how he specifically hated being the clone who (as far as he was aware) inherited Big Boss' recessive genes.
- A quick google reveals some stuff about a story from the bible featuring related characters by the names of David and Eli; David being Solid Snake's real name.
- ...Look at this asshole. If that's not the look of someone you just know you're going to shoot down whilst he's flying around in a Hind D, then I don't know what is.
It's probably a common piece of speculation at this point, and even I have thought as such for a while now. But I noticed there was no thread discussing it, and with the release date of Ground Zeroes now out in the open, this got me thinking me about MGSV again and brought me back to this.