I guess in theory that could be an "if everything broke right" maximum upside. Hard to imagine but if I tried to build a mental case for it and dream big I'd think back to that 6 game stretch his rookie season where he averaged 8.5 targets and 5.6 receptions a game, which would pro-rate to 144/96 in a 17 game season. That was mainly with Mike White and Flacco while he was a rookie so in year three with a likely much better QB it's not out of realm of possibility. Nothing I would expect, but again you are asking for upside and not projections.
I feel comfortable projecting him as the #2 receiver on the team, would not surprise me in the least if he led the team in receptions. I do think he's a 70 catch guy, that's more of a projection, not upside.