I have concerns regarding the fix, As you negate the condition, Before the fix it was not displaying Index node for Tables but after the fix it will not display it for Partition tables.
But when I read the Postgres docs it say,
Partitions may themselves be defined as partitioned tables, using what is called sub-partitioning. Partitions may have their own indexes, constraints and default values, distinct from those of other partitions. Indexes must be created separately for each partition. SeeCREATE TABLE for more details on creating partitioned tables and partitions.
Please find the attached patch to fix RM #3180Index node is missing from the tree view of the table node. This is a regression of one of the older commit.