There was no growth on the dwarf lilac this year. No leaves. No flowers. However, there are a couple of suckers growing from the base. Is it possible they will mature to full grown lilac or dwarf lilac trees? Also, is it possible for the dwarf lilac tree to be dormant for one year and then recover the next?
It is always so upsetting when one of our beloved plants succumb to diseases. From your photo it appears that you have a dwarf Korean Lilac Top Graft. The Korean Lilac was grafted on top of a rootstock. The fact that you did not see any leaves this season it is more than likely that your tree did not come through last winter. unscathed. You can check the viability of your plant by scrapping off a bit of the bark with your fingernail. If you see green wood underneath then part of the plant is still viable. However, with this years formation of leaves to photosynthesis and produce sugars your tree will more than likely not put forth new growth next spring.
The shoot growth that you observe at the bottom of the rootstock will not be that of a dwarf Korean Lilac but is more likely from the common lilac- Syringa reticulata.