Is Grim Reaper getting a buff?

Yes, in the November update. The lead designer agreed that Grim Reaper has few AoE and damage-over-time (DoT) skills, so it's strong in PvP but falls behind when farming. Hunting efficiency will be improved in the class balance changes planned for November. How big the change is hasn't been announced.

Netmarble's official Grim Reaper class video.
Short answer

In its November 6 dev answers, Netmarble said Grim Reaper's farming will be improved in the November class balance update. Skirmish cross-server PvP is next, and an option to hide Bloodshape effects is coming.

What is Skirmish, and when is cross-server PvP coming?

Netmarble says Skirmish, a cross-server PvP mode, is next. Matchmaking follows the world structure: in some regions two servers form one world and share one Marketplace. After Skirmish, a periodic shuffle will reorganise cross-server matchmaking to narrow the gap between busy and quiet servers. No date yet.

The lead designer's other answers

November 6 dev answers
TopicAnswer
Login queue (1,800 players) Server capacity is capped on purpose, for hunting-ground competition and the in-game economy. The queue is being monitored.
Bloodshape aura effects An option to show or hide effects on Heroic-grade and higher Bloodshapes is planned.
Auto-accept party invites Not coming. If the party leader sets join requirements and auto-approval, anyone who qualifies joins with one click.
English voice-over Not planned. Character voices are Korean.
Inventory expansion Unchanged: 4 slots for 50 Diamonds, same price from the first expansion to the last. Farmed Diamonds work too, and there's a Character Warehouse.

November 6 restart: can't connect?

All servers restarted one by one on November 6 at 05:00 (UTC-5), each in under 10 minutes. You download new data when you reconnect; on PC, fully close the game and update through the Netmarble Launcher. Characters inside dungeons were removed when the restart began. Rewards and packs from the previous maintenance: VAMPIR November 4 update.

Weighing up a class? See the VAMPIR Grim Reaper guide and what's the best class in VAMPIR?