What I can see happening sometimes is that the author doesn't have a page, but the page on the science clearly cites the person that ended up winning the Nobel.

In this case, the Wikipedia article on chirped pulse amplification has cited Donna Strickland as a co-inventor since 2008 (https://en.wikipedia.org/w/index.php?title=Chirped_pulse_amp...).

For phage displays, George P. Smith is not mentioned but at least cited as far back as 2008 (https://en.wikipedia.org/w/index.php?title=Phage_display&old...). By 2012, George P. Smith is directly mentioned. (https://en.wikipedia.org/w/index.php?title=Phage_display&old...)

Notable in this context meaning notable to the general public. But wikipedia isn't for original research, and so it needs some external institution to validate notability to the general public. A Nobel prize is one such mechanism.

Wikipedia is not just for the general public, many pages go into a lot of detail, and to people who understand the details of certain subfields of chemistry, these people might be well-known. I'm not a chemist, so I wouldn't know in this case.

The novel prise isn’t given to people already considered notable by the general public. Of the 200 and some physicists who are Nobel laureates most dedicated physics students would struggle to name more than a dozen, let alone arbitrary members of public.

They become notable to the public when they receive the award because if it’s public recognition, but they are awarded it based on their research contributions being notable.