To be quite honest - I don't understand this huge debate about a new contract or not. Every single manager who fails to get the result that is required, will get fired. So the only difference is if the payout the manager will get is 3 million or 7 million.
If you have faith in a manager you give him a new contract - if you don't you fire him. Managers dont sit out their contract and is then being replaced - that only happens in case of someone like Wenger or Ferguson.
If Solskjaer fails to reach top-4 and we dont do really well next season - he will get fired. If he reaches top-4 for the second year in a row, he deserves a new contract. If the results dont continue to improve - he will eventually get fired anyway so what is the problem ?