Patreon pledges are subscriptions, (monthly)
The only way to get benefits from patreon, is to pledge
When the payment is processed and charged, you're given access for a month, if you're unable to pay after that, you lose access.
"Not being able to pay" also includes "Not paying"... or in otherwords, canceled. - But you will only have the one month's access, so if there's an update the next day after that, you're out of luck.
additionally.
If you pledge /right now/ with the way it is currently set up
You would gain access for the month of July. (July 1st to August 1st)
If you pledged and then stopped, You would lose access August 1st - Discord Benefits may very well end immediately upon stopping though, even if before the patreon period. - So its possible other 3rd party services, like Itchio may close access immediately on stopping as well.