Imho he'll be here next season. Yes, he's come on in the last few weeks, but he was no world beater for the first 6 months of the season. Just happened to find a rich vein of form at the right time.
Why are we so eager to mentally sell every player with an ounce of promise? Regardless of your opinion of TF and SISU, they didn't sell the kitchen sink in January, so why would they do so in the summer? I imagine there will be relegation clauses in contracts, so wages should be manageable, and I refuse to believe they won't want to go straight back up. Yesterday was the start of the journey, not the end.