This is plausibly the Turkish POV on Egyptian threats. Increasingly everyone understands that conflict averse Egypt is serious about intervening, except, I've been told, Turkey. Task some Egypt allies have faced is persuading Turkey that Sisi is serious. https://twitter.com/ragipsoylu/status/1275089970332684288

The arguments that Egypt's threats are empty are base it seems on faulty analysis ie "we don't think Egypt has capabilities and is tied up in Sinai hence won't follow through." What matters is Egypt's perception of its capabilities, and what it sees as its choices, not others'.

Is Egypt enthusiastic about intervening? Not in the least. Sisi's speech and its international messaging are clear on a preference for a negotiated settlement. An intervention if redlines ignored would be more a political and negotiation tactic than a military one.

Incidentally, if Egypt does militarily intervene, this wouldn't be the first time it launched a war to be taken more seriously in negotiations, and against analysis downplaying its capabilities/intent.

No similarity otherwise of course between Libya and 1973, but some misperceptions are common to both situations