Here's what we've seen so far:
From the Yosemite website:
First-Come, First-Served Permits in 2020
Wilderness permits are not available in the park in 2020. Beginning June 11, 40% of permits that would normally be available first-come, first-served are instead available by lottery two weeks in advance. Beginning June 11, you can submit a request 15 days in advance of a hike, with the lottery running 14 days in advance. Unreserved permits remain available up to nine days in advance. It is not possible to obtain a wilderness permit reservation fewer than nine days in advance.
From hiking start dates from June 11 to June 25, any unreserved permits that are part of the 60% quota are available by online reservation.
And another source notes:
Wilderness permits will NOT be issued in park. In order to receive your permit via email, you must receive permit education from a ranger over the phone. Rangers will be calling the phone number on file for your reservation or you may call (209) 372-0826. Following a phone call, your permit will be emailed to you.
You can not enter the park without a physical copy of your wilderness permit, parking pass and ID. You will not be required to obtain additional reservations to enter into the park.
Rangers will check wilderness permits at the gate. Only participants of a wilderness trip will be provided access.
Other things you need to know:
• Trailheads along Tioga Road are not accessible at this time. Yosemite rangers can not issue a permit for trailheads between Crane Flat and Tioga Pass.
• You may not enter the park with this permit more than one day before your trip start date.
• If Half Dome is a part of your wilderness reservation, you must confirm payment with Yosemite Conservancy before your permit is issued.
• Bear-Resistant Food Storage is required on all overnight stays in Yosemite Wilderness. We strongly encourage you to purchase or rent an allowed bear canister, before arriving in the park. Canister will be available for rent at select Wilderness Centers during limited hours at Yosemite Wilderness Permit Station for $5 per week (deposit required). Bear canisters will NOT be available at Hetch Hetchy.
• You may not enter the park with this permit more than one day before your trip start date. For permit holders starting on June 5th, there is no ability to enter one day in advance. For those starting after June 5th, your permit will authorize you to stay at a Backpackers' Campgrounds one night before and one night after your trip. The cost is $6 per person, per night.
• Check Current Wilderness Conditions for trail conditions and timely updates.
• With limited resources due to COVID-19 and high risks involved in search and rescue operations, please plan your trip carefully and ensure all safety precautions are taken. Response times may be delayed if you call for help. Proper planning is integral to preventative search and rescue. Use attached form to create a wilderness plan and share with responsible parties before you come to the park.
• While Wilderness is a place to get away, you will likely see other visitors and rangers. Please follow social distancing guidelines and respect the safety of other visitors and rangers when you encounter them. Please respect plants and animals throughout the park by following Leave No Trace ethics.