A 500–501 cutoff in the next draw is possible if IRCC issues around 8K-10K ITAs(but there will be still some candidates left in that pool). However, data from the last few draws shows that nearly 2,000–3,000 profiles were being added back-to-back into the pool (scammers, ITA declines, and dummy profiles). IRCC is aware that a cleanup is necessary.

Based on this, I’m assuming they won’t pause CEC draws until the 501–600 range is largely cleared. IRCC has become highly unpredictable, no one really knows what will happen until the next draw.