Do you mean the league lost its tax exemption. EINs do not expire. Business may be able to consider sponsorship as a business expense but not a charitable deduction if the league is no longer a charity.
The businesses should be able to write-off sponships as business expenses, which avoids dealing with whether the league gets its tax exempt status reinstated.
You either misunderstood or the officials mis-stated what happened. EIN numbers do not "expire." An EIN has nothing to do with the league's status as a tax-exempt charitable organization. That is a status granted by the Internal Revenue Service. It does not "expire" but it can be lost because of non-compliance with the rules and laws that govern it. If the organization applied for and received designation as a "charitable tax-exempt" organization it meant that donations to it were deductible by the donor and that it did not pay income tax on its tax-exempt income (but it would pay tax on its income which was unrelated to its tax-exempt activities). Bottom line, we can't really help because we don't have correct facts. And, I don't think you were given correct facts by the organization. From a business perspective I would never advise a business client to take a deduction for money given to an organization in the position that yours is in unless it was specifically for advertising. That would be a business expense. But there had better be advertising and the business would need to have proof of it.
DISCLAIMER: This is not specific legal advice and does not establish an attorney/client relationship.