Of course it is subject to revisions because it is not a real month picture. The reporting time is the 16th of the month to the 15th of the month they are reporting so for July the last 16 days are not there while the last 15 days of June are.
Why because it would be impossible for employers to report month end numbers and get the numbers in to report. And the reporting is voluntary. so a company may report one month and then not at all.
The report can be automated but many companies just can't afford it.
So basically the BLS does have to revise from time to time and Trump is still stupid.