By allowing poor rank avatars to show by default, this could encourage the use of Marketplace avatars (From a simple search, around half of these seem to be poor rank). For now, many unsavvy players will be seeing impostors or fallbacks of these marketplace avatars, despite them being much better optimized than a Very Poor.
On Android mobile and iOS, the limit should stay as Medium by default due to the low power of most devices. The draw calls may be too expensive there 💧.