Why would my tax code 150 show a cycle number but then a date of 00-00-0000?

IRS Transaction Code 150 signifies that a tax return has been filed and posted to the account.

A transaction date is the effective date of a transaction on a tax account, and the cycle date represents the date the IRS processed the transaction.

See this article from the IRS Taxpayer Advocate for more information on understanding IRS transcripts.