A lot will come down to how they invest and who they replace Howe with, but I think a lot of things went their way this year to make them look better than they are, Don't get me wrong, they can be effective and get a result, but they aren't a winning team yet. But no Europe and a half the traditional top 6 having off years certainly benefitted them. But Liverpool, Tottenham and Chelsea could all bounce back next season and send them back done to 6 or 7, especially since they'll have to deal with Europe now.
For me personally I look at that Newcastle team and they are an effective team at grinding out results, but they don't have world class players that will stand out individually. Maybe Guimaraes, but let's be honest, most of us never even heard of him before Newcastle, so we don't really know if he is a standout player that can do the same wherever, he's still just a part of that team to me.
Having said that, they could just splash massive cash and anything is possible.