If the US congress extended the Section 5 preclearance requirement in the Voting Rights act another 25 years in 2006, why might it not apply in 2020?

Question

Wikipedia's Voting Rights Act of 1965; Amendments says:

Congress enacted major amendments to the Act in 1970, 1975, 1982, 1992, and 2006. Each amendment coincided with an impending expiration of some or all of the Act's special provisions. Originally set to expire by 1970, Congress repeatedly reauthorized the special provisions in recognition of continuing voting discrimination. Congress extended the coverage formula and special provisions tied to it, such as the Section 5 preclearance requirement, for five years in 1970, seven years in 1975, and 25 years in both 1982 and 2006.

I don't need a python program to know that 2006 + 25 is demonstrably larger than 2020, but something caught my attention in US attorney general Merrick Garland's discussion as covered in the CNN video Justice Department suing Georgia over voting restrictions after 04:54:

And because the upcoming redistricting cycle may be the first since 1960 to proceed without the key preclearance provision of the voting rights act, we will publish new guidance to make clear the voting protections that apply to all jurisdictions, as they redraw their electoral maps. (my transcription)

Question: If the US congress extended the Section 5 preclearance requirement in the Voting Rights act another 25 years in 2006, why might it not apply in 2020? Why might redistricting proceed without the provision?

Answer 1

The Supreme Court had invalidated part of the Voting Rights Act in their 2013 Shelby County v. Holder landmark decision that rendered Section 5 ineffective.

From The New York Times:

The majority held that the coverage formula in Section 4 of the Voting Rights Act, originally passed in 1965 and most recently updated by Congress in 1975, was unconstitutional. The section determined which states must receive clearance from the Justice Department or a federal court in Washington before they made minor changes to voting procedures, like moving a polling place, or major ones, like redrawing electoral districts.

Section 5, which sets out the preclearance requirement, was originally scheduled to expire in five years. Congress repeatedly extended it: for five years in 1970, seven years in 1975, and 25 years in 1982. Congress renewed the act in 2006 after holding extensive hearings on the persistence of racial discrimination at the polls, again extending the preclearance requirement for 25 years. But it relied on data from the 1975 reauthorization to decide which states and localities were covered.

[ ... ]

The decision did not strike down Section 5, but without Section 4, the later section is without significance — unless Congress passes a new bill for determining which states would be covered.

(emphasis mine)

As summarised by the Department of Justice:

On June 25, 2013, the United States Supreme Court held that it is unconstitutional to use the coverage formula in Section 4(b) of the Voting Rights Act to determine which jurisdictions are subject to the preclearance requirement of Section 5 of the Voting Rights Act, Shelby County v. Holder, 133 S. Ct. 2612 (2013). The Supreme Court did not rule on the constitutionality of Section 5 itself. The effect of the Shelby County decision is that the jurisdictions identified by the coverage formula in Section 4(b) no longer need to seek preclearance for the new voting changes, unless they are covered by a separate court order entered under Section 3(c) of the Voting Rights Act.

Lastly, as redistricting is done every ten years, following the release of the Census, the 2020 redistricting cycle is the "first since 1960 to proceed without the key preclearance provision".