Thanks for answering before I asked.
I’m reading the IRS IR 2020-58 to say the ‘Filing Deadline’ is extended to July 15, which is different than allowing for a penalty free extension of time to file, as might happen during a natural disaster. And Pub 590-A is clear, IRA contributions may be made by the tax filing deadline, excluding extensions…and the new rulings says July 15 is the new filing deadline. Hence, IRA contributions will be extended.
Even if the custodian doesn’t identify the IRA contribution as being for 2019, the IRA owner can still do it. But it will be important for such custodians to correct this as their 5498 will be wrong as will their identification of another 2020 contribution (made for 2020) as an excess contribution for 2020.