There’s only one scenario where I would be fine with Regina entering the pub and meeting the man with the Lion tattoo.
It plays out like this…
Tink leads Regina to the pub, telling her that the man inside, the man with the lion tattoo is her One True Love.
Regina sees the tattoo, but balks, and walks away from her destiny. Moments later she rethinks, turns back, and enters the pub looking for the Lion.
However, in the interim, while Regina balks, two strangers cross paths within the pub. In that moment the man with the lion tattoo leaves his seat and walks out through the back door, crossing paths another man who walks in through the same door and sits in Robin’s empty chair.
In walks Regina. And it is revealed that Oaken, now seated in Robin’s chair also has a lion tattoo.
And, Tink is banished for naughty-fairy behavior.
Yeah I’d be fine with that. Cuz if you change the past, but neglect the little minor details, anything’s possible.