If Wasm does become as pervasive as JVM i.e. a universal VM of sorts, there will be plenty of IoT equipment using it since the trend now for anything "embedded" that doesn't demand ultra low power consumption is to use a full Linux system à la Raspberry Pi. A company optimizing for a tight memory/performance budget and whose purpose does not require high uptime across the entire fleet can simply use traditional blue-green deployments or something.