Did the original 'Old Man Logan' comic storyline have a significant impact on the wider Marvel Universe?

Yes, 'Old Man Logan' had a substantial impact. While initially an alternate future story, the character of Old Man Logan was later brought into the main Marvel continuity during the *Secret Wars* event in 2015. He replaced the deceased mainstream Wolverine for a period, starring in his own ongoing series and joining X-Men teams, profoundly influencing the direction of the X-Men line and expanding the character's legacy beyond its original limited series.