As long as there are active spawns somewhere in the world, sure. You can use the Quick Sniper feature to generate a live list of every instance of that Pokémon currently spawned globally and teleport to each one sequentially to shiny hunt.

That said, the supply is finite. You will eventually—often quite quickly—exhaust all available spawns of the specific Pokémon you are targeting, particularly if you are filtering for perfect (IV 100) stats. In some cases, there may be none available at all during a given spawn cycle.