Not the last update, but the one before that: 2.13 changed the default ZenNode configurations. Most importantly, the "Fast" and "Normal" options no longer create BLOCKMAP or REJECT lumps. This makes saving maps quicker, and decreases the filesize, especially with larger maps.
BLOCKMAP has been optional since 2.1, as SRB2 can create one if it's not provided with the map. Not that it takes up much of the nodebuilding time, but it's not really necessary either.
REJECT has always been optional, but used to be a significant optimization for line-of-sight checks in the past. However, the effects are reportedly not significant unless a map has a
lot of enemies, and it does not take slopes into account. Most importantly, building the REJECT lump takes up exponentially more time* and space the more sectors a map has. Larger maps, like CEZ2 or ERZ2, have REJECT lumps that are almost as big as all other map lumps combined!
However, for cases where those lumps might be needed, two "Slow" nodebuilding settings were added: one that builds REJECT, and one that builds REJECT and BLOCKMAP. If you're convinced that REJECT makes a significant difference for your map, I would recommend using one of these "Slow" options when preparing your map for a release. This can be changed in the Game Configurations menu (F6), under the Nodebuilder tab.
* This used to be even worse with SRB2DB, where building a REJECT lump would take up the vast majority of nodebuilding time, easily taking several minutes per save on large maps...