The VA has internal suspenses in order to keep your claim moving. I believe their internal suspense states that they need to provide the PEB your proposed rating within 15 calendar days of receipt of request from a PEB for a proposed rating decision. They must also set a claim level suspense that is 10 days after the receipt of request. The suspense reason and claim status at this point is "Ready For Decision". You might be able to use this to your advantage when talking on the phone with someone to get a better timeline or know exactly where your case is at. Some customer service agents won't give you anything, but some are very helpful. Especially those working the VERA phone calls.
With that being said, they aren't held to any regulation outside of their organization and depending on the amount of claims, things could take longer. From what I've seen, some members have received their proposed ratings back in a timely manner while others take 30-90 days at the VA level. Those that take longer may have more referred conditions or conditions that they're claiming, or there could be issues with their file that delay processing. In my scenario, the VA was taking longer due to my initial claim form (21-526EZ) not being submitted / uploaded in my file by my MSC. Of course, I only found this out after scheduling a VERA phone call at the regional office where my claim was. The VA was not very proactive in reaching out to me beforehand.
I hope this helps a little!