וְיִמָּלְאוּ אֲסָמֶיךָ שָׂבָע וְתִירוֹשׁ יְקָבֶיךָ יִפְרֹֽצוּ׃
As Dr. Howell notes in the video, the word שָׂבָע can mean something like plenty or satiety. If it's understood as plenty, these barns are redundantly described ("filled with plenty"), but this redundancy does illustrate that abundance.
The ESV and NKJV both have "filled with plenty," and the Vulgate ("et implebuntur horrea tua saturitate") is comparable. The NIV seems to go a bit further with "filled to overflowing."
My German translation of Proverbs goes the other way and takes שָׂבָע to mean simply satiety: "so werden deine Scheunen voll werden" ("so your barns will become full").
