I think they made a strategic mistake.

The Treaty of London was secret (and possibly illegal). Italy could have negotiated an equivalent secret treaty with Austria, where Friuli would be exchanged for neutrality, and wait to the last moment to enter the war.

Italy got Friuli and Süd Tirol, but I think the human cost was too high to get two territories that were not Italian for centuries. Also, what would be Italian even mean? And, consider that ww1 was not a moral war, in the sense ww2 is, i.e. you are fighting countries that are almost democratic if not fully so (except Russia surely).