Nor sure what the situation is in the US but generally probation and parole are different things altogether.
Parole is a provision that the offender is allowed to complete the term of a sentence of imprisonment without being confined in recognition of their promise not to reoffend and subject to a return to prison at the discretion of the judiciary.
Probation is a sentence whereby the offender is placed under the authority of the court (the court has probate) for a set period of time. Probation usually replaces imprisonment although there may be imprisonment if the terms of probation are not met.
Since a person on parole is technically serving a period of imprisonment, and an offender is debarred from voting when imprisoned, it follows that the right to vote is removed during parole. I see no evidence at all that probation involves loss of voting rights. I certainly see no evidence to support your assertion that in California: 'Once you are released from prison, you are considered a "Felon" for life, and never allowed to vote again = for your entire life'
But what purpose is served by taking away the right to vote? If a lot of people are doing something that is considered "criminal", then perhaps the laws need to be changed.
Drinking beer when you are 20 years old is a serious crime, but should it be? I once asked a friend in Italy what the drinking age was there, and after thinking about it, she didn't think there was one. She distinctly remembered going to the local grocery store as a small child and bringing home wine and bread - all by herself.
If a lot of people are turned into criminals by ridiculous laws, then they will not be able to vote in a way that changes these laws.
EDITED: 25 May 2017 16:13 by HARRYN