There's very little incentive for Newcastle to loan him out, his contract runs out in 2021 so by next summer he'll be 29 with 12 months left on his deal - his value would plumett, particularly on those wages.
I wouldn't be surprised if Cardiff, Huddersfield or Stoke do eventually get him for about 12m. Or maybe someone like Sheffield United will.
His wages present as much of a problem to those teams as they do to us.
Looking at his current deal at Newcastle he is costing them £4.5m a year i.e. wages £2.5m plus depreciation on a £10m fee over a 5 year contract (the fee has long been paid to Palace but that is not how the cost of transfers is accounted for).
Assuming he is sold for £12m and to make that happen Newcastle buy out his contract for £3m and his new club give him a £1m a year contract for 3 years. He is costing his new club £5m a year and that might be as a Championship club. That club also has the same issue with that Newcastle have with him now is that strikers heading into their 30's are very difficult to sell because clubs are starting to wise up to the fact that they often decline quite early in their careers.
Newcastle will loan him out if Bruce is not going to use him because that is better than getting nothing and another high scoring season in the Championship will enhance his limited value whereas a season as a largely none playing squad player would probably reduce to nearly zero.