Here is the current picture on Yawgmoth in Modern.
Yawgmoth is a fringe-to-medium presence archetype right now. Over the last 30 days it appeared in 9 tournaments but with very low entry counts per event, sitting well outside the top 15 archetypes by presence. The format is currently dominated by Boros Energy (20.6% presence), Jeskai Blink (10.4%), and Affinity (7.9%), which makes it hard for a combo-creature deck like Yawgmoth to command significant table share.
That said, the performance numbers are actually quite encouraging when it does show up. Excluding mirrors, Yawgmoth posted a 59.5% winrate (25-17) over the last 30 days, and its best week (April 13-19) went an impressive 80% (8-2). The core shell looks updated with Badgermole Cub at 4 copies in every list and Malevolent Rumble as a consistency engine alongside Walking Ballista as the classic combo kill. The archetype appears to be alive and punching above its weight, but it remains a specialist choice with a small player base rather than a mainstream meta player.
If you are considering picking it up, the winrate data suggests the deck is well-positioned against the current field when piloted by players familiar with it, but expect to face lots of Boros Energy, Jeskai Blink, and Affinity.
Sources: Data from 12 tournaments (75% MTGO, 25% Melee) over the last 30 days.