FWIW, I have manned phone banks, the last time four years ago for the Romney campaign. There was absolutely NO outreach to volunteers to be part of the process.
The process is not a secret. And any one with any sense knows that campaigns need volunteers so the excuse of there was no outreach is silly. If a person is interested in being part of a party it is obvious that they have to do more than show up at one election. This take my hand and walk me through life attitude that Trumpster’s have is exhausting.