This rule provides ongoing monitoring for high-value transactions at merchants with recent category changes or status updates.

Triggers alert when:
1. Merchant has been newly categorized or recategorized within past 90 days
2. High-value transaction processed (category-specific thresholds apply)
3. Insufficient historical data for new category assignment

Category change monitoring is important because:
- Business model changes may indicate account takeover
- Legitimate business sold to new owners (unknown fraud risk)
- Merchant attempting to abuse category change for fraud
- System recategorization may not reflect actual business operations
- Transaction patterns expected to change during category transition period

90-day monitoring window allows:
- Validation that category change reflects actual business
- Detection of fraudulent category manipulation
- Baseline establishment for new business model
- Early warning if category change was fraud precursor

Alert-based approach enables review without disrupting legitimate businesses undergoing normal evolution or expansion.