This is going to be an interesting test case to see if the community here can be forgiving. I'm estimating we can let bygones be bygones in the face of apparent contriteness. I don't think it's the community's responsibility to determine whether somebody is really sorry or if they're just sorry they got caught. The real test comes in the ongoing behavior. If the plagiarism ceases then I for one welcome you to the fold. Everybody deserves a fresh start.
As this platform proceeds the social norms need to be fleshed out. Forgiveness seems to me to be a given since everybody has the capacity to mess up. We wouldn't want our own feet held to the fire for every dishonest thing big or small.
Where more thought must be taken is the issue of ill-gotten gains. A plagiarist can be rewarded lavishly before reforming their ways. That puts them ahead of others who took a more honest approach to posting. Is it earned?
As a community I would like to see us come to a decision about what ought to be done. Nothing? Do we urge the person to contribute a portion of their plagiarized gains to a charity? How about offering it to @robinhoodwhale or @curie or any number of other worthwhile projects striving to pay it forward?