Major brands have been moving away from using Pantone colours as a method of defining their visual brand identity for quite some time.
The reason for this is that brands want (and need) absolute consistency of colour across marketing platforms, packaging formats, POS, etc. It has been shown that even small, hard to notice variations in colour reproduction can have a measurable impact on sales.
Using a Pantone reference alone fails to fulfil this requirement for various reasons. Pantone books are not printed on the same substrate as all of the required formats and they are not even all the same colour! This makes them a difficult (some would say impossible) target for manufactures. That said, they perform a valuable role as a starting point for selecting and defining colour.
Once the starting point is defined, major brands then move into a process of print trials and proof verification. The results of that process are then fed back into the design process.
For example: consider a fizzy drink that comes in red packaging - Pantone 200 is a nice dark red. You would then ask the manufactures of the cans, bottle labels, bottle caps, multipacks, POS, etc, etc to run a print trial to get their best match to Pantone 200. None of them will hit it exactly. You then take the furthest away of the colours and supply that as a sample to all the other manufacturers and you go again. (If it is important that the brand colour be reproduced out of CMYK then this will often be the governor). You now (probably) have a much closer grouping. Another iteration or two and you will have a consensus of a red that can be achieved by everyone, consistently. You then define and distribute the specification of this colour as "standard fizzy drink red" and everybody matches to that, knowing that it is achievable. Along with this, you would output digital proofs, based on press fingerprints, to verify that they match the final print. All of these trials are signed off by the brand manager (or similar). The Pantone 200 swatch that was the original inspiration is now confined to history.
The colour that is included in the brand style guide is now "standard fizzy drink red" and the definition of how to reproduce it may include various colour definitions, such as Lab, RGB, CMYK, etc. It may also include information regarding specific ink suppliers and/or substrate manufacturers that were part of the trial process and therefore can provide proven results. Colour data (i.e. CXF) files and/or print profiles may also be distributed alongside the style guide.
There would then need to be a process of colour measurement and control applied to the production of the packaging, etc. This might include press passes or samples being supplied to brand managers, for instance. All of these supplied samples would need to adhere to an agreed tolerance, usually measured with a photo spectrometer, and excessive variation would be a cause for concern, discussion and potential contract cancellation.
As the length of this answer might imply, this is a HUGE subject, an expensive process and (for some people) a full time job.
This is not within the scope (or budget) of small brands and companies and is therefore only a consideration for major brands. It is however, a worthy consideration of designers who contribute to (or aspire to contribute to) the visual brand identities of major global brands.