I don't like -lynn but I do like -lin.
Peterlin is interesting, I'd assume there's a story behind it. People are reacting like it's a trendy thing but to me the -lin ending for boys names sounds more historical (?)
The only thing is that I'd think Peterlin would sound more like one solid name if it was PEH-ter-lin instead of PEET-er-lin, because if the
Peter part is just pronounced like the name
Peter then it seems like less of one name and more like "a name plus an extra suffix".