Transferring an input signal sourced from an unrelated clock domain implies, that setup- and hold times can't be kept. If the input changes within the setup/hold window, the result can't be predicted, it can be either the old or the new signal state. Metastability must not be involved at all, it's simply a case of signal skew and jitter making the sampling result unknown.
The example shown by std_match is not about multiple bits, it's a single binary signal with two edges. The edge position is however varying by one clock cycle.
If the edge position of binary signals becomes unsure, you can't transmit multibit signals, e.g. representing binary numbers, without additional measures reliably. There are different methods to overcome this issue:
- in special cases, gray encoding of the multibit data can help
- handshake or qualifier signals that mark a stable signal state. The transmission can occur only at a fraction of the clock speed