It is difficult to answer your question in such a general and absolute way.
These rules are based on "cascading 50 ohm building blocks with lines" thinking. In reality, it depends on how much effect one mismatched line will have on other blocks further down the signal path.
If we have a wire and then a series MIMCAP and then another wire, then we have to look at the total length of this path. For the signal, this is one transparent signal path. But if we have a line between two functional blocks (mixers, amplifiers, ...) then I would look at the length of this wire alone, if the functional blocks at the end of the wire "isolate" a possible mismatch from the rest of the circuit.
So there is some "gray zone" in this estimate, as you can see.
Also, this discussion about "short lines don't matter" is based on a medium impedance level in the signal path, such as cascading 50 ohm blocks.
If we look at very low or very high impedance levels, then even small capacitance or inductance values can be critical. Example: Adding a short line in the emitter/source (=extra inductance) is critical even though it is a short line, because here we have a low impedance level. Adding a wide line in a high impedance location will kill your performance because the little extra capacitance is critical at this impedance level. So the "short lines don't matter" is based on a medium impedance level in the signal path, such as cascading 50 ohm blocks.