Learn Portuguese (Portugal): Este reencontro é muito inesperado!

You could say Nós reencontrámo-nos (We met each other again). By attaching the reciprocal pronoun -nos to the verb reencontrar (to meet again), you show that the action happens mutually between the people involved, meaning "each other."

How are the words reencontro and inesperado built from other common Portuguese words?

Reencontro combines the prefix re- (again) with the noun encontro (meeting/encounter). Inesperado uses the negative prefix in- (un-) attached to esperado (expected). Esperado, in turn, is the past participle of the common verb esperar (to expect or to wait).

Why do we use é (from the verb ser) instead of está (from estar) to say the reunion is unexpected?

We use ser because being "unexpected" is treated as a fundamental, defining characteristic of this specific event. While we use estar for temporary physical or emotional states (like being tired or cold), describing the permanent nature or qualities of an event always requires ser.

As a quick refresher, why do we use Este (this) instead of Esse (that) here?