It looks like this would connect up I-74 from Rockingham to I-95. Maybe they think that's more important than connecting up around Rockingham. Besides, then they'd have to explain where I-73 goes.
Yeah you are correct, it will still leave a gap because the main part of Rockingham Bypass (I-73/I-74 from US 220 to US 74 west of town) isn't going to be constructed until 2026. The section that is being funded is the section of US 74 between Rockingham and Laurinburg.
They're currently constructing the interchange at the south end of the bypass too, right, or just the north?
The northern end of the bypass is currently under construction. 
Only the north? Is the south end scheduled soon after or will that be done with the main bulk in 2026?
Yeah the section of US 220 between the Ellebre exit (I-73/74 Exit 25) and Harrington Rd is the only part of the bypass that is currently under construction. This section includes interchanges with Haywood Cemetery and Dockery Rd (Exit 23) and US 220 itself (Exit 22) where it will leave Future I-73/74 Bypass for the final time (US 220 currently ends at US 1 just south of Rockingham in case you didn't know).
The rest of them will start in 2026, according to the NCDOT's STIP map:
Route / City: US 220 BYPASS / FUTURE I-73 / FUTURE I-74
Description: ROCKINGHAM BYPASS, US 74 BYPASS WEST OF ROCKINGHAM AT SR 1109 (ZION CHURCH ROAD) INTERCHANGE TO SOUTH OF SR 1140 (OLD CHARLOTTE HIGHWAY)
SPOT ID: H090231-A
Funding Category: DIV
ROW Year:
Const. Year: 2026
Project Cost: $70,200,000.00
Comments: RIGHT OF WAY IN PROGRESS
Route / City: US 220 BYPASS / FUTURE I-73 / FUTURE I-74
Description: ROCKINGHAM BYPASS, SOUTH OF SR 1140 (OLD CHARLOTTE HIGHWAY) TO SOUTHWEST OF SR 1304 (HARRINGTON ROAD)
SPOT ID: H090231-B
Funding Category: DIV
ROW Year:
Const. Year: 2026
Project Cost: $74,500,000.00
Comments: RIGHT OF WAY IN PROGRESS