For a new process, new facility, or novel product surely this would be needed. However, with the OP's query it is not a new process, new facility, or novel product. One can use the data and information from previous products, or current products using the same process to validate their shelf-life. This is quite common in the beverage industry since so many new products can be formulated with a few ingredient changes.
This has very much been my experience, and generally the auditors with the relevant scope approval to be auditing such facilities will have a reasonable understanding of the same principles. It's a bit reminiscent of the thread a few weeks ago that was discussing the pitfalls/merits of interpretation in the auditing of a standard
I can't speak for the US market, but it is certainly not that uncommon in the EU/UK for "best by" ("best before" for the UK) dated ambient-stable beverages, i.e. those for which shelf life and indeed general microbiological stability isn't a limiting factor, to have a shelf life set based to an extent on supply chain operational requirements and realistically exceeding the duration for which the product is actually at its best. A longer life helps meet demanding minimum life on delivery requirements set by retailers and helps at the consumer end as people think they are buying a fresher product if they see it still has e.g. 18 months left.
In practice a lot of these products don't actually last that long, and will taste, smell and/or look rather tired some way before the actual date. For example I'd strongly recommend against drinking any canned beer from certain large brands anywhere near the stated best before date
It's virtually never a problem in practice as the stock is sold through and used long before it reaches end of life, but there is typically an allowance made by the businesses to accept/expect a small number of quality complaints from consumers who have had the misfortune drinking something near the BBE.
We have a few brands for whom we pack who do exactly this - we warrant our own validated shelf life, and label a duration somewhat longer at the customers' undertaking with their labels, as its the only way they can meet what are often ludicrous minimum shelf life requirements set by their distributors.
Experience of auditors has generally been that they look at one product, have a brief discussion around the rationale behind the "best before" rather than "use by" date (although many don't even bother doing that once they've reviewed HACCP, and that's almost always the first thing audited), ask about ongoing shelf life monitoring, and move on.
I've no idea how acceptable it would be for SQF to adopt a combined "validation of (general) process" approach, combined with a high frequency shelf life monitoring plan for the first batch, and further action determined based on the findings of that?
Nonetheless it's what I'd be doing as a BRC certified site.