The "buy LN coins directly" step seems curious, possibly because they need a way to assess demand for LN withdrawals. With Wumbo channels and LN withdrawals, Bitfinex have that huge advantage as an exchange over the others, manifest as the potential for their own liquidity to be far greater than other exchanges without Lightning support. In a (likely soon) bullrun, this will make Bitfinex the most attractive platform to traders who wish to have more control over risk management. Once a 2nd major exchange enables LN deposits & withdrawals, all of them will be essentially forced to do it so as not to lose out in the arbitrage battle.
They also seem to want to add Tether deposits/withdrawals via LN. As Tether is an Omni token, this could mean
OmniBOLT support.
However questionable Tether is as a concept, that would be a pretty remarkable facility for Bitfinex traders to have at their disposal. I thought that Tether had changed into an Ethereum based token though?