Can sucralose form a syrup?
Syrup is just a very concentrated solution of sugar. 
Because of the high concentration (for instance 65% w/w for USP Syrup, the concentration that avoids bacterial growth) the viscosity increases, and the solution gets syrupy. 

In the case of sucralose, the solubility is much lower than that of sugar. 
That is normally not an issue, since the sweetening potency is about 600 times higher, at moderate concentrations (80 ppm sucralose have the same potency as 5% sugar). 
But to make a syrup, you need a very high concentration. 
With a solubility of 28.3 g/100 mL, the viscosity will, probably, be much lower than that of sucrose syrup. 

To compare, note that the viscosity of a 30% sugar solution is 3.21 mPa•s, while that is a 60% sugar solution is 56.76 mPa•s.
Take into account that sucralose differs from sucrose only in the exchange of three $\ce{-OH}$ for $\ce{-Cl}$.