More likely FRN are due to concerns about the inability to sell notes at near 0.0% rates unless it carries the potential to adjust-up with any rate rise. Of course, they could also adjust down with any rate decline. Wonder if they will allow them to go negative? Wouldn't that be a shocker for the buyers of FRNs.
"There was a lengthy discussion regarding the bid-to-cover ratios at recent Treasury bill auctions. It was broadly agreed that flooring interest rates at zero, or capping issuance proceeds at par, was prohibiting proper market function. The Committee unanimously recommended that the Treasury Department allow for negative yield auction results as soon as logistically practical." Letter written by JPM and GS to Treasury.
I still say that negative yield auctions on t-bills will set the stage for bank runs. My mattress gives better results.