The current one affects anyone trying to file a new petition (including those that are cap-exempt). If someone wants to switch employers they cannot use premium processing, which affects their ability to travel internationally and/or move jobs.
> Starting May 26, 2015, USCIS will temporarily suspend premium processing for all H-1B extension of stay petitions until July 27, 2015. During this time frame, petitioners will not be able to file Form I-907, Request for Premium Processing Service, for a Form I-129, Petition for a Nonimmigrant Worker, requesting an extension of the stay for an H-1B nonimmigrant.
In summary, yes the 2015 stay was just for extensions. No it wasn't for all applications.
Terminology matters.
In particular, I don't think many skilled employees with a global choice of employers are going to move to a country for a 3 or 6 year stint with deportation waiting at the end of the period. The costs and trouble of moving don't make it worthwhile, and it's hard to predict what life will bring - it's best to maximize all options. So I think anyone migrating to the US on a H1-B visa will also end up going through the permanent residency application process, just so they don't face a cliff edge after 6 years. That would make them migrants at the start of the process, rather than some kind of seasonal workers.