No it isn't, at least not when it's an ARM CPU. This is because ARM CPUs have very low IPC, something that's quite important when you start emulating higher gen consoles like the Gamecube. Mainly because these consoles require a lot of instructions for emulation (because of how much more complex they are), and a higher IPC = more instructions that can be completed each cycle. This is also why, pre Ryzen anyways, AMD CPUs weren't usually recommended for Dolphin or PCSX2 over Intel, because their IPC are very, very low vs Intel CPUs. That's why a dual core Pentium G3258 running at 3.2GHz can beat out an 8 core AMD FX8350 running at 4.2GHz in pretty much every Dolphin benchmark, the Intel CPU's IPC is likely 2-3x the AMD's.
ARM CPUs have an equally low IPC, meaning they have to work much harder to achieve any kind of high-instruction based processing...like emulation. Losing out on 1GHz across all 4 cores, in this case, would drastically reduce performance compared to the Shield TV. The Switch would be able to pick up a bit of that lost performance because it would have much lower OS overhead (since the Switch is obviously not running Android, thankfully
), but it still wouldn't perform as well a Shield TV would, even if Nintendo optimized the hell out of it (which they probably already did for the Shield version).
If we see Gamecube VC on the Switch, it'll either be some kind of port (like Wind Waker or Twilight Princess HD on the Wii U) or it'll be those "easier to emulate" Gamecube games, like Animal Crossing or Luigi's Mansion (at least, if they can figure out a digital->analog trigger fix). Anything harder to emulate would likely require a lot of speed hacks to run well on the Switch, something that nobody really wants (at least, if they want a decent experience).