That's my impression. I wonder if they're going to watch the A318 in operation with European carriers first and see what it's in-service numbers are. Clearly, USA operators of 73G's or 738's--AA, DL, and WN--aren't impressed with the 736. All three of these carriers have big fleets of old 100-seat a/c to replace, yet have shunned the 736.
100-seat planes is a vital segment of the airline business, but the economics of the industry have driven it into limbo. Low-fare carriers have driven fares down on enough routes that major carriers don't seem to think the new mainline narrobody 100-seaters (A318, 736) can make them money. It's too much metal to carry too few seats, apparently.
Yet the network airlines and their affiliates are hesitant about the lighter-weight, and undoubtedly more economical, 928 Jet, CRJ-900, etc., because of scope clause issues with unions. (Gotta love unions, all about employees, the hell with industry economics or pax) IS the 928 Jet a regional ac because it's made by Embraer, or is it a mainline a/c because it carries almost 100 pax? That'll be a fun question at the bargaining table.
At medium-size airports in the US, 100-seat aircraft were dominant in the '80s-notably the DC-9-30 and 737-200. Many of their routes don't justify 125- or 150-seat a/c at good enough frequencies for business travelers. These airports especially are watching their service turn excessively quickly into RJ's, because new, economical, and labor-friendly 100-seaters aren't on the market.
Need a new airline paint scheme? Better call Saul! (Bass that is)