Do you think it's rude to get a message from someone but don't reply, yet you're online since you're updating your status? Are they being rude?

[JNT-LEGGO]

Not really

However if it's an urgent or important message that's a little rude.

Also if they're consistently almost habitually ignoring you.

Trust me, even though it's online after while you can tell the difference between people who are genuinely less chatty or just busy and people who are being neglectful and disrespectful.