What is the allusion here?

To the Maundy Thursday story (at least in John) where Jesus washes his disciples' feet. This is considered gross and taboo but Jesus is like "no, I gotta do it, and maybe this will give you a hint as to how to treat others."

Any others?

It's vague, but "neighbors are...varied in color and race" could be a reference to the Good Samaritan (which we read today so it was on my mind). Jesus makes the point of "sometimes the neighbor you're supposed to love is someone from a hated outgroup, deal."

Have the lyrics changed since the last edition?

Yeah. The first verse now reads "master who acts as a slave for them" instead of "pours out himself." I suspect this is a revert to the original in an effort to be more on-point and the previous version I knew was an adaptation dismissed as too wishy-washy?

Why does this song have a subtitle?

Because it's also in Spanish and that's the alternate-language title. Not all the translated songs have subtitles, maybe just the ones with other languages present in this text? We'll see.

Is the translation good?

To my knowledge, yes. My Spanish is middling at best, but it's the only other language I know, so. Since the original doesn't rhyme, there wasn't much need to bend the translation to make it fit.

The one thing that stood out to me was Un pueblo que busca en esta vida/la gran liberación becomes "the people who long to claim the promise, God's liberating word." The liberating part makes sense, but "busca en esta vida" would literally translate as "seek in this life." Is this a social justice (in the original sense) focused message of "don't worry about heaven, change the world here?"

Any cool (bilingual) turns of phrase?

"El mundo, por la guerra, sangra sin razón," rendered as "The lifeblood of the world is shed in mindless war," is pretty neat.