look, all our rights are tied to being law abiding citizens.
Even with free speech, you do NOT have the right to yell FIRE in a crowded theater. Of course, we tend to beleive if someone does yell fire, THEN you lock them up, you don't gag every person going into the theater just in case they maybe feel like yelling FIRE!
The constitution is silent on punishment, as long as it is not cruel and unusual. There is nothing unconstitutional about throwing a murder or even a shoplifter in jail for life.
If we choose to relax some restrictions and allow them out on parol, we can still retrict other rights (such as freedom of association, you can't hang out with gang members any more) just like if they were still in jail.
If we eventually dial that back even further, where they keep the moniker "Felon" but otherwise are free, then we are still within the constitution to withhold rights, such as firearms or voting. After all, we'd be within our rights to have them in jail still.
In the same vein, if someone is a convicted child molestor, just because they serve their time doesn't wash away the crime. They will never be allowed to be a teacher, daycare provide, pediatricain, or other jobs that work with kids.