“Keep the Illustrator format” isn’t realistic if Illustrator is going away at their workplace.
If the company is discontinuing Illustrator internally, then relying on the .ai format is pointless nothing else fully supports it. Only Illustrator can guaranteed-open AI files with complete fidelity.
PDF is not an editable substitute for Illustrator
People often assume PDFs can be reopened in a vector program as if nothing changed. That’s just wrong. PDF is a final format meant for output, not editing. Illustrator has a backend option to Save with Compatible Illustrator file, which means the file can be opened in Illustrator - but it’s important to open in the same version as previous, I’ve seen strange occurances if not.
Things like:
appearance-only clipping masks
text engine differences
transparency flattening
spot colors
symbol instances
artboards
embedded ICC profiles
live effects
blends & mesh gradients
variable fonts
patterns
DO NOT round-trip cleanly into Affinity / Corel / Inkscape / or anything.
Even Illustrator itself only edits PDFs properly when the file contains the special “PDF + embedded AI data” hybrid structure. Other apps as far as I know ignore that AI portion entirely.
You lose editability, structure, naming, layer logic, and stylistic integrity.
EPS is obsolete
EPS is old PostScript tech from the 1980s.
No transparency
No layers
No color management, no live blending modes
No mesh gradients
No effects, no artboards
No proper Unicode text support
No ICC metadata
No modern features in general
Exporting 10,000 pages to EPS destroys modern content. And modern apps treat EPS as a legacy import format, not something to edit reliably.
Totally unsuitable for a curriculum with modern graphics.
SVG is RGB-only, web-oriented, and incomplete
SVG is fantastic for the web, but terrible as a universal print/layout round-trip format.
Limitations:
RGB only (no CMYK, no spot colours critical for print curricula)
Limited text features
Limited or no support for:
appearance stacks
patterns
compound strokes
artboards
blend modes
live effects
clipping/opacity masks (often flattened or misinterpreted)
And each program interprets SVG differently (Affinity, Figma, Illustrator, Inkscape, Corel all render SVG differently).
SVG breaks the moment you leave basic shapes and flat colours.
Exporting to PDF/SVG/EPS doesn’t magically make 10,000 Illustrator documents “editable in another program.”
They become output files, not working files.
No modern layout or vector application can open AI files (or PDF/SVG/EPS exports) with full fidelity, especially for something the size of an educational curriculum.
What actually is a reasonable approach
If its genuinely have 10,000 pages of curriculum content built in Illustrator:
Find out how each file was saved
If “PDF-compatible AI” was used best chance of recovery
If saved as pure .ai → much harder
Pick one host application (Affinity Designer, CorelDRAW, or even InDesign if restructuring)
Test a batch
Import 20–30 files and check:
fonts
layers
text flows
spot colours
linked images
bleeds
effects
Long-term
A curriculum of this scale really belongs in InDesign or a database-driven system, not Illustrator.