Maybe so, but one church in Jackson, MS hardly qualifies as the Antiochian Orthodox Church in America.
I can't say much regarding the Diocese of Miami and the Southeast, but in the Diocese of Wichita and Mid-America, kneeling on Sundays is prohibited for the exact reason you stated earlier. I would think that this practice is the norm elsewhere and that what you observed in Jackson was an exception, but I'm just guessing.
In fact a few weeks ago, I was in Orlando in a beautiful and very upscale Greek Orthodox Church (the Holy Trinity, right off Interstate 4), and a visiting priest from Greece was reminding everyone that kneeling, especially during the 40 days after the resurrection is strictly prohibited.
I spoke with him after the Divine Liturgy and mentioned the First Ecumenical Council and he said "You are absolutely right! In my part of Greece, no one kneels, but in some they do, an we have to teach them not to, just like here."
Again, a church is our spiritual home, not a theater where we go to watch a performance, so pews are not the proper thing to have in a church. We are supposed to stand in awe. That element of "performance" is what resulted in the early Latin deviation in the reception of the Eucharist for the clergy only at one point in time.