It's the truth. The Orpik-Jerebek pairing was routinely pinned in its own zone. There's a reason they gave up an even-strength goal against in both of the first two playoff games. Djoos only gave up 5 ES goals against the next 22 games of the playoffs combined. The Orpik/Djoos pairing was demonstrably better than the Orpik/Jerebek pairing, and that's largely because Djoos was a great compliment to Orpik and Djoos provided the pairing the ability to get out of their own zone, and helped cover for Orpik's lack of mobility when forechecked.
You can compare Djoos' 2017-18 regular season stats to Orpik's here:
Player Season Totals - Natural Stat Trick
It's a pretty gaping disparity. Djoos' GF% was 59% to Orpik's 41%. Djoos' expected goals against was barely more than half of Orpik's. This is backed up by every scoring chance, shot, and shot attempt-based metric. There's no question Djoos had more offensive deployments, but he was also seeing a fair chunk of Top 4 time prior to the acquisition of Kempny.
And their playoffs (mostly spent together):
Player Season Totals - Natural Stat Trick
The cult of Orpik glosses over how limited of a player he was by the time he joined the Capitals. It's not always the "stay at home" guy who bails out his partner. It's often the puck carrier is the one to act as the pressure relief when the opposing team is forechecking.