The guy said that this, his work, his project, which is a GBA emulator in Javascript, would not work well on the 3DS. This is because it has to run in the browser, and is in a not-the-best-for-emulation language in the first place. He mentioned that, as an alternative, it would have to be done like other emulators, closer to the hardware (that is, not interpreted script) and with a different model if it were to achieve decent speed.
You took that to mean more than it did, in the terms of emulation on the 3DS at all.