If they are found guilty of even some of the charges, the precedent in the PL has been points deductions. At the very minimum I think they will get a very large points deduction that will be enough to relegate them at the end of this season.
If the charges are proven then they should be expelled from the PL and banned from returning for at least 5 years and even then, only with a change of ownership which can be proven to have zero connection to the current owners.
This is not some minor PSR / FFP breach, this is alleged conspiracy to present fraudulent accounts for the purpose of skirting rules they had signed up to.